Add CXX cross-compile detection into Makefile after it was removed from gyp.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/405113002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22509 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Makefile

@@ -399,11 +399,16 @@ clean: $(addsuffix .clean, $(ARCHES) $(ANDROID_ARCHES) $(NACL_ARCHES)) native.cl
 # GYP file generation targets.
 OUT_MAKEFILES = $(addprefix $(OUTDIR)/Makefile.,$(BUILDS))
 $(OUT_MAKEFILES): $(GYPFILES) $(ENVFILE)
+	$(eval CXX_TARGET_ARCH:=$(shell $(CXX) -v 2>&1 | grep ^Target: | \
+	        cut -f 2 -d " " | cut -f 1 -d "-" ))
+	$(eval V8_TARGET_ARCH:=$(subst .,,$(suffix $(basename $@))))
 	PYTHONPATH="$(shell pwd)/tools/generate_shim_headers:$(shell pwd)/build:$(PYTHONPATH):$(shell pwd)/build/gyp/pylib:$(PYTHONPATH)" \
 	GYP_GENERATORS=make \
 	build/gyp/gyp --generator-output="$(OUTDIR)" build/all.gyp \
 	              -Ibuild/standalone.gypi --depth=. \
-	              -Dv8_target_arch=$(subst .,,$(suffix $(basename $@))) \
+	              -Dv8_target_arch=$(V8_TARGET_ARCH) \
+	              $(if $(filter $(CXX_TARGET_ARCH),$(V8_TARGET_ARCH)), \
+	              -Dtarget_arch=$(CXX_TARGET_ARCH),) \
 	              $(if $(findstring optdebug,$@),-Dv8_optimized_debug=2,) \
 	              -S$(suffix $(basename $@))$(suffix $@) $(GYPFLAGS)