Allow the bit/res/set bit index to be determined at link time (#1654)

This increments the object file revision number from 11 to 12
since it adds a new `RPN_BIT_INDEX` command.

test/asm/invalid-instructions.err

@@ -10,8 +10,10 @@ error: invalid-instructions.asm(5):
     syntax error, unexpected bc, expecting hl
 error: invalid-instructions.asm(6):
     syntax error, unexpected number, expecting hl
+warning: invalid-instructions.asm(7): [-Wtruncation]
+    Expression must be 3-bit
 error: invalid-instructions.asm(7):
-    Bit number must be between 0 and 7, not 8
+    Invalid bit index 8 for BIT
 error: invalid-instructions.asm(8):
     Invalid address $40 for RST
 error: Assembly aborted (8 errors)!

test/link/bit-res-set-bad.asm

@@ -0,0 +1,5 @@
+SECTION "test", ROM0
+Label:
+bit Label - 1, a
+res Label + 8, [hl]
+set Label | $ff00, b

test/link/bit-res-set-bad.out

@@ -0,0 +1,4 @@
+error: bit-res-set-bad.asm(5): Value $ff00 is not a bit index
+error: bit-res-set-bad.asm(4): Value $8 is not a bit index
+error: bit-res-set-bad.asm(3): Value $ffffffff is not a bit index
+Linking failed with 3 errors

test/link/bit-res-set.asm

@@ -0,0 +1,10 @@
+SECTION "test", ROM0
+Label:
+bit Label + 0, b
+bit Label + 1, c
+res Label + 2, d
+res Label + 3, e
+set Label + 4, h
+set Label + 5, l
+bit Label + 6, a
+set Label + 7, [hl]

test/link/bit-res-set.out.bin

@@ -0,0 +1 @@
+ֻ@ֻIֻ’ֻ›ֻהֻםֻwֻ‏