Merge pull request #1817 from acqn/PPFix

[cc65] More preprocessor fixes

test/val/bug1643.c

@@ -0,0 +1,12 @@
+/* bug #1643, macro expansion in #include */
+
+#define MKSTR(a)        MKSTR_IMPL(a)
+#define MKSTR_IMPL(a)   #a
+#define BUG1643_H       bug1643.h
+
+#include MKSTR(BUG1643_H)
+
+int main(void)
+{
+    return BUG1643_RESULT;
+}

test/val/bug1643.h

@@ -0,0 +1,13 @@
+/* bug #1643, macro expansion in #include */
+
+#define STDIO_H     <stdio.h>
+#include STDIO_H
+
+#ifdef string
+#undef string
+#endif
+
+#define string      0!%^&*/_=
+#include <string.h>
+
+#define BUG1643_RESULT 0