Add -B/--backtrace option to RGBASM and RGBLINK (#1787)

test/link/section-union/align-conflict.out

@@ -1,6 +1,10 @@
-error: Section "conflicting alignment" is defined with 4-byte alignment (offset 0) at section-union/align-conflict.asm(7), but with address $cafe at section-union/align-conflict.asm(7)
+FATAL: Section "conflicting alignment" is defined with 4-byte alignment (offset 0), but also with address $cafe
+    at section-union/align-conflict.asm(7)
+    and also:
+    at section-union/align-conflict.asm(7)
+Linking aborted with 1 error
 ---
-error: <stdin>(18):
-    Section already declared as aligned to 4 bytes (offset 0)
-FATAL: <stdin>(18):
-    Cannot create section "conflicting alignment" (1 error)
+error: Section already declared as aligned to 4 bytes (offset 0)
+    at <stdin>(18)
+FATAL: Cannot create section "conflicting alignment" (1 error)
+    at <stdin>(18)

test/link/section-union/align-ofs-conflict.out

@@ -1,6 +1,10 @@
-error: Section "conflicting alignment" is defined with 8-byte alignment (offset 7) at section-union/align-ofs-conflict.asm(7), but with 16-byte alignment (offset 14) at section-union/align-ofs-conflict.asm(7)
+FATAL: Section "conflicting alignment" is defined with 8-byte alignment (offset 7), but also with 16-byte alignment (offset 14)
+    at section-union/align-ofs-conflict.asm(7)
+    and also:
+    at section-union/align-ofs-conflict.asm(7)
+Linking aborted with 1 error
 ---
-error: <stdin>(18):
-    Section already declared with incompatible 8-byte alignment (offset 7)
-FATAL: <stdin>(18):
-    Cannot create section "conflicting alignment" (1 error)
+error: Section already declared with incompatible 8-byte alignment (offset 7)
+    at <stdin>(18)
+FATAL: Cannot create section "conflicting alignment" (1 error)
+    at <stdin>(18)

test/link/section-union/assert.out

@@ -1,6 +1,7 @@
-error: section-union/assert.asm(11): Force failing the build
+error: Force failing the build
+    at section-union/assert.asm(11)
 Linking failed with 1 error
 ---
-error: <stdin>(30):
-    Assertion failed: Force failing the build
+error: Assertion failed: Force failing the build
+    at <stdin>(30)
 Assembly aborted with 1 error!

test/link/section-union/bad-types.out

@@ -1,6 +1,10 @@
-error: Section "conflicting types" is defined with type HRAM at section-union/bad-types.asm(7), but with type WRAM0 at section-union/bad-types.asm(7)
+FATAL: Section "conflicting types" is defined with type HRAM, but also with type WRAM0
+    at section-union/bad-types.asm(7)
+    and also:
+    at section-union/bad-types.asm(7)
+Linking aborted with 1 error
 ---
-error: <stdin>(18):
-    Section already exists but with type HRAM
-FATAL: <stdin>(18):
-    Cannot create section "conflicting types" (1 error)
+error: Section already exists but with type HRAM
+    at <stdin>(18)
+FATAL: Cannot create section "conflicting types" (1 error)
+    at <stdin>(18)

test/link/section-union/bank-conflict.out

@@ -1,6 +1,10 @@
-error: Section "conflicting banks" is defined with bank 4 at section-union/bank-conflict.asm(5), but with bank 1 at section-union/bank-conflict.asm(5)
+FATAL: Section "conflicting banks" is defined with bank 4, but also with bank 1
+    at section-union/bank-conflict.asm(5)
+    and also:
+    at section-union/bank-conflict.asm(5)
+Linking aborted with 1 error
 ---
-error: <stdin>(14):
-    Section already declared with different bank 4
-FATAL: <stdin>(14):
-    Cannot create section "conflicting banks" (1 error)
+error: Section already declared with different bank 4
+    at <stdin>(14)
+FATAL: Cannot create section "conflicting banks" (1 error)
+    at <stdin>(14)

test/link/section-union/data-overlay.out

@@ -1,7 +1,7 @@
 FATAL: Section "overlaid data" is of type ROM0, which cannot be unionized
 Linking aborted with 1 error
 ---
-error: <stdin>(18):
-    Cannot declare ROM sections as UNION
-FATAL: <stdin>(18):
-    Cannot create section "overlaid data" (1 error)
+error: Cannot declare ROM sections as UNION
+    at <stdin>(18)
+FATAL: Cannot create section "overlaid data" (1 error)
+    at <stdin>(18)

test/link/section-union/different-data.out

@@ -1,7 +1,7 @@
 FATAL: Section "different data" is of type ROM0, which cannot be unionized
 Linking aborted with 1 error
 ---
-error: <stdin>(16):
-    Cannot declare ROM sections as UNION
-FATAL: <stdin>(16):
-    Cannot create section "different data" (1 error)
+error: Cannot declare ROM sections as UNION
+    at <stdin>(16)
+FATAL: Cannot create section "different data" (1 error)
+    at <stdin>(16)

test/link/section-union/different-ofs.out

@@ -1,6 +1,10 @@
-error: Section "conflicting alignment" is defined with 8-byte alignment (offset 7) at section-union/different-ofs.asm(7), but with 8-byte alignment (offset 6) at section-union/different-ofs.asm(7)
+FATAL: Section "conflicting alignment" is defined with 8-byte alignment (offset 7), but also with 8-byte alignment (offset 6)
+    at section-union/different-ofs.asm(7)
+    and also:
+    at section-union/different-ofs.asm(7)
+Linking aborted with 1 error
 ---
-error: <stdin>(18):
-    Section already declared with incompatible 8-byte alignment (offset 7)
-FATAL: <stdin>(18):
-    Cannot create section "conflicting alignment" (1 error)
+error: Section already declared with incompatible 8-byte alignment (offset 7)
+    at <stdin>(18)
+FATAL: Cannot create section "conflicting alignment" (1 error)
+    at <stdin>(18)

test/link/section-union/different-size.out

@@ -1,7 +1,7 @@
 FATAL: Section "different section sizes" is of type ROM0, which cannot be unionized
 Linking aborted with 1 error
 ---
-error: <stdin>(16):
-    Cannot declare ROM sections as UNION
-FATAL: <stdin>(16):
-    Cannot create section "different section sizes" (1 error)
+error: Cannot declare ROM sections as UNION
+    at <stdin>(16)
+FATAL: Cannot create section "different section sizes" (1 error)
+    at <stdin>(16)

test/link/section-union/different-syntaxes.out

@@ -1,7 +1,7 @@
 FATAL: Section "different syntaxes" is of type ROM0, which cannot be unionized
 Linking aborted with 1 error
 ---
-error: <stdin>(18):
-    Cannot declare ROM sections as UNION
-FATAL: <stdin>(18):
-    Cannot create section "different syntaxes" (1 error)
+error: Cannot declare ROM sections as UNION
+    at <stdin>(18)
+FATAL: Cannot create section "different syntaxes" (1 error)
+    at <stdin>(18)

test/link/section-union/org-conflict.out

@@ -1,6 +1,10 @@
-error: Section "conflicting address" is defined with address $beef at section-union/org-conflict.asm(7), but with address $babe at section-union/org-conflict.asm(7)
+FATAL: Section "conflicting address" is defined with address $beef, but also with address $babe
+    at section-union/org-conflict.asm(7)
+    and also:
+    at section-union/org-conflict.asm(7)
+Linking aborted with 1 error
 ---
-error: <stdin>(16):
-    Section already declared as fixed at different address $beef
-FATAL: <stdin>(16):
-    Cannot create section "conflicting address" (1 error)
+error: Section already declared as fixed at different address $beef
+    at <stdin>(16)
+FATAL: Cannot create section "conflicting address" (1 error)
+    at <stdin>(16)

test/link/section-union/same-export/out.err

@@ -1 +1,5 @@
-error: "Same" is defined as a label at section-union/same-export/b.asm(2), but as another label at section-union/same-export/a.asm(2)
+FATAL: "Same" is defined as a label, but also as another label
+    at section-union/same-export/b.asm(2)
+    and also:
+    at section-union/same-export/a.asm(2)
+Linking aborted with 1 error

test/link/section-union/split-data.out

@@ -1,7 +1,7 @@
 FATAL: Section "mutually-overlaid data" is of type ROM0, which cannot be unionized
 Linking aborted with 1 error
 ---
-error: <stdin>(18):
-    Cannot declare ROM sections as UNION
-FATAL: <stdin>(18):
-    Cannot create section "mutually-overlaid data" (1 error)
+error: Cannot declare ROM sections as UNION
+    at <stdin>(18)
+FATAL: Cannot create section "mutually-overlaid data" (1 error)
+    at <stdin>(18)