mkimage: make it easier to run syntax checkers on grub-mkimagexx.c

This makes it so you can treat grub-mkimagexx.c as a file you can build
directly, so syntax checkers like vim's "syntastic" plugin, which uses
"gcc -x c -fsyntax-only" to build it, will work.

One still has to do whatever setup is required to make it pick the right
include dirs, which -W options we use, etc., but this makes it so you
can do the checking on the file you're editing, rather than on a
different file.

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

util/grub-mkimage32.c

@@ -19,4 +19,6 @@
 # define ELF_ST_TYPE(val)		ELF32_ST_TYPE(val)
 #define XEN_NOTE_SIZE 132
 
+#ifndef GRUB_MKIMAGEXX
 #include "grub-mkimagexx.c"
+#endif

util/grub-mkimage64.c

@@ -19,4 +19,6 @@
 # define ELF_ST_TYPE(val)		ELF64_ST_TYPE(val)
 #define XEN_NOTE_SIZE 120
 
+#ifndef GRUB_MKIMAGEXX
 #include "grub-mkimagexx.c"
+#endif

util/grub-mkimagexx.c

@@ -50,6 +50,15 @@
 
 #pragma GCC diagnostic ignored "-Wcast-align"
 
+#define GRUB_MKIMAGEXX
+#if !defined(MKIMAGE_ELF32) && !defined(MKIMAGE_ELF64)
+#if __SIZEOF_POINTER__ == 8
+#include "grub-mkimage64.c"
+#else
+#include "grub-mkimage32.c"
+#endif
+#endif
+
 /* These structures are defined according to the CHRP binding to IEEE1275,
    "Client Program Format" section.  */