MIPS: Add interpreter. Enable MIPS build rules.

src/buildvm_asm.c

@@ -120,7 +120,10 @@ static void emit_asm_wordreloc(BuildCtx *ctx, uint8_t *p, int n,
     exit(1);
   }
 #elif LJ_TARGET_MIPS
-  UNUSED(sym);  /* NYI */
+  fprintf(stderr,
+	  "Error: unsupported opcode %08x for %s symbol relocation.\n",
+	  ins, sym);
+  exit(1);
 #else
 #error "missing relocation support for this architecture"
 #endif
@@ -200,6 +203,9 @@ void emit_asm(BuildCtx *ctx)
 	  ".save {r4, r5, r6, r7, r8, r9, r10, r11, lr}\n"
 	  ".pad #28\n");
 #endif
+#if LJ_TARGET_MIPS
+  fprintf(ctx->fp, ".set nomips16\n.abicalls\n.set noreorder\n.set nomacro\n");
+#endif
 
   for (i = rel = 0; i < ctx->nsym; i++) {
     int32_t ofs = ctx->sym[i].ofs;