Initial import of AMBuild infrastructure for C++ projects.

Former-commit-id: 53baa4f8c25525674f5e71f8f6ff2663928500ab

compiler/amxxpc/amx.cpp

@@ -775,7 +775,7 @@ static void expand(unsigned char *code, long codesize, long memsize)
     do {
       codesize--;
       /* no input byte should be shifted out completely */
-      assert(shift<8*sizeof(cell));
+      assert(size_t(shift)<8*sizeof(cell));
       /* we work from the end of a sequence backwards; the final code in
        * a sequence may not have the continuation bit set */
       assert(shift>0 || (code[(size_t)codesize] & 0x80)==0);