build/ac-macros/macosx.m4: workaround AC_RUN_IFELSE

The SVN_LIB_MACHO_ITERATE macro contains an AC_RUN_IFELSE test that
doesn't work when cross-compiling. However, this macro is related to
testing Mac OS X APIs, so in the context of Buildroot, we don't care,
and the test program is not even going to build. So we simply
workaround this by turning the test into an AC_COMPILE_IFELSE.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

Index: b/build/ac-macros/macosx.m4
===================================================================
--- a/build/ac-macros/macosx.m4
+++ b/build/ac-macros/macosx.m4
@@ -24,7 +24,7 @@
 AC_DEFUN(SVN_LIB_MACHO_ITERATE,
 [
   AC_MSG_CHECKING([for Mach-O dynamic module iteration functions])
-  AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
     #include <mach-o/dyld.h>
     #include <mach-o/loader.h>
   ]],[[