Add test for #line in ASM contexts

This one test it in BASIC listings

Author: boriel

tests/functional/line_err.bas

@@ -0,0 +1,7 @@
+DIM q as UByte = 1
+ASM
+NOP
+#line 25
+END ASM
+DIM q = 1: REM this error should show at line 26, not line 6!
+

tests/functional/test_errmsg.txt

@@ -172,4 +172,7 @@ due_par.bas:5: error: Syntax error. Unexpected end of file
 error_array.bas:3: error: Invalid assignment. Variable z$() is an array
 >>> process_file('prepro76.bi')
 prepro76.bi:2: error: this is an intended error
-
+>>> process_file('line_asm.bi')
+line_asm.bi:26: warning: this should be line 26
+>>> process_file('line_err.bas')
+line_err.bas:5: error: Variable 'q' already declared at line_err.bas:1