build: check if a simple C program runs

This will be helpful for working out why AIX is failing

lib/replace/test/simple.c

@@ -0,0 +1,8 @@
+/* simple program to make sure the compiler is OK */
+#include <stdio.h>
+
+int main(void)
+{
+	printf("Hello world\n");
+	return 0;
+}

lib/replace/wscript

@@ -73,6 +73,15 @@ def configure(conf):
 
     conf.env.DISABLE_SHARED = Options.options.disable_shared
 
+    # see if we can compile and run a simple C program
+    conf.CHECK_CODE('#include "test/simple.c"',
+                    addmain=False,
+                    define='HAVE_SIMPLE_C_PROG',
+                    mandatory=True,
+                    execute=True,
+                    msg='Checking simple C program')
+
+
     # check for rpath
     if not conf.env.DISABLE_SHARED and conf.CHECK_RPATH_SUPPORT():
         conf.env.RPATH_ON_BUILD   = not Options.options.disable_rpath_build