Avoid treating labels and macros differently in column 1 (#1515)

Fixes #1512

test/asm/lexer-hack.asm

@@ -0,0 +1,28 @@
+MACRO mac
+	println "got {d:_NARG} args: \#"
+ENDM
+
+; indented, these were always macro invocations
+	mac
+	mac ro
+	mac : ld a, 1
+
+; in column 1, we historically treated these as labels
+mac
+mac ro
+mac : ld b, 2
+
+SECTION "test", ROM0
+
+; a colon makes these into labels
+	Label1: ld c, 3
+Label2: ld d, 4
+
+; a macro invocation when already defined as a label
+	Label1 args
+; and a label definition when already defined as a macro
+mac: ld e, 5
+
+; the space before the colon matters!
+	undef :
+undef :

test/asm/lexer-hack.err

@@ -0,0 +1,9 @@
+error: lexer-hack.asm(22):
+    "Label1" is not a macro
+error: lexer-hack.asm(24):
+    'mac' already defined at lexer-hack.asm(1)
+error: lexer-hack.asm(27):
+    Macro "undef" not defined
+error: lexer-hack.asm(28):
+    Macro "undef" not defined
+error: Assembly aborted (4 errors)!

test/asm/lexer-hack.out

@@ -0,0 +1,6 @@
+got 0 args: 
+got 1 args: ro
+got 2 args: : ld a,1
+got 0 args: 
+got 1 args: ro
+got 2 args: : ld b,2

test/asm/syntax-error-after-syntax-error.asm

@@ -1,10 +1,11 @@
-MACRO mac
-	println "got {d:_NARG} args"
-ENDM
-	mac
-	mac 42
-notmac
-mac
-mac 42
-mac::
-mac ::
+def x = 1 ; so far so good...
+def n equ 2 + * / ^ 3 ; oops
+def s equs "no closing quote, lol
+section "test", rom0 ; good again
+ld a, 42 ; keep going...
+ld xor, ret ; oh no :(
+label1: ; yes...
+label2:: ; yes...
+label3::: ; no!
+halt stop abort ; please
+println "finally!"

test/asm/syntax-error-after-syntax-error.err

@@ -1,13 +1,11 @@
+error: syntax-error-after-syntax-error.asm(2):
+    syntax error, unexpected *
+error: syntax-error-after-syntax-error.asm(3):
+    Unterminated string
 error: syntax-error-after-syntax-error.asm(6):
-    syntax error, unexpected newline, expecting : or ::
-error: syntax-error-after-syntax-error.asm(7):
-    syntax error, unexpected newline, expecting : or ::
-    To invoke `mac` as a macro it must be indented
-error: syntax-error-after-syntax-error.asm(8):
-    syntax error, unexpected number, expecting : or ::
-    To invoke `mac` as a macro it must be indented
+    syntax error, unexpected xor
 error: syntax-error-after-syntax-error.asm(9):
-    'mac' already defined at syntax-error-after-syntax-error.asm(1)
+    syntax error, unexpected :
 error: syntax-error-after-syntax-error.asm(10):
-    'mac' already defined at syntax-error-after-syntax-error.asm(1)
+    syntax error, unexpected stop, expecting newline or end of buffer or ::
 error: Assembly aborted (5 errors)!

test/asm/syntax-error-after-syntax-error.out

@@ -1,2 +1 @@
-got 0 args
-got 1 args
+finally!