The native compiler on OpenIndiana is gcc. Modify GNU make to suit.
We don't define GCC_IS_NATIVE since this also modifies the native
lex and yacc defitions and makes the POSIX tests fail.

This patch is taken from OmniOS on May 9th, 2021
--- make-4.4.1/src/default.c.orig
+++ make-4.4.1/src/default.c
@@ -529,8 +529,8 @@
     "CC", "gcc",
     "OBJC", "gcc",
 #else
-    "CC", "cc",
-    "OBJC", "cc",
+    "CC", "gcc",
+    "OBJC", "gcc",
 #endif
 #ifdef MAKE_CXX
     "CXX", MAKE_CXX,