Fix grammar for line comments

Line comments consume a line feed, so an LF token is not emitted after.
Thus, line comments can appear between arguments, splitting an
instruction between lines. Also, a line comment cannot be on the last
line without a final LF.

asm.l

@@ -70,7 +70,7 @@
 (?i:end)                    { return I_END; }
 
 ","                         { return COMMA; }
-";"(.*)\n                   { ; }
+";".*                       { ; }
 \'(\\.|[^\\\'\n])\'         { yylval->string = strdup(yytext); return CHAR; }
 \"(\\.|[^\\\"\n])*\"        { yylval->string = strdup(yytext); return STRING; }
 -?[01]+[bB]                 { yylval->string = strdup(yytext); return NUMBER; }

tests/parsing/regress/pass/ignored_line_comment.asm

@@ -0,0 +1,3 @@
+; This was parsed as `push 1`, instead of `push / 1`.
+push ; comment
+1

tests/parsing/regress/pass/ignored_line_comment.ws

@@ -0,0 +1,2 @@
+
+