Add tests

Author: boriel

tests/functional/due_inc_main.bas

@@ -0,0 +1,8 @@
+' Main.bas
+
+#include "due_par.bas"
+
+Test(5)
+
+pause 0 
+

tests/functional/due_par.bas

@@ -0,0 +1,4 @@
+SUB test(code as Ubyte)
+	k=in(12234
+END SUB
+

tests/functional/test_errmsg.txt

@@ -163,4 +163,8 @@ llb.bas:3: error: Undeclared function "f$"
 >>> process_file('opt2_include_unused.bas')
 func0.bas:5: warning: Using default implicit type 'float' for 'f'
 func0.bas:4: warning: Function 'f' is never called and has been ignored
-
+>>> process_file('due_par.bas')
+due_par.bas:2: error: Syntax error. Unexpected end of line
+>>> process_file('due_inc_main.bas')
+due_par.bas:2: error: Syntax error. Unexpected end of line
+due_par.bas:5: error: Syntax error. Unexpected end of file