Rewrite Makefile rules for Android to allow parallel execution

Makefile

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 160 matching lines @@
                  builddir="$(shell pwd)/$(OUTDIR)/$@"
 
 native: $(OUTDIR)/Makefile.native
         @$(MAKE) -C "$(OUTDIR)" -f Makefile.native \
                  CXX="$(CXX)" LINK="$(LINK)" BUILDTYPE=Release \
                  builddir="$(shell pwd)/$(OUTDIR)/$@"
 
 $(ANDROID_ARCHES): $(addprefix $$@.,$(MODES))
 
 $(ANDROID_BUILDS): $(GYPFILES) $(ENVFILE) build/android.gypi \
-                   must-set-ANDROID_NDK_ROOT
-        @tools/android-build.sh $(basename $@) $(subst .,,$(suffix $@)) \
-                                $(OUTDIR) $(GYPFLAGS)
+                   must-set-ANDROID_NDK_ROOT Makefile.android
+        @$(MAKE) -f Makefile.android $@ \
+                ARCH="$(basename $@)"   \
+                MODE="$(subst .,,$(suffix $@))" \
+                OUTDIR="$(OUTDIR)" \
+                GYPFLAGS="$(GYPFLAGS)"
 
 # Test targets.
 check: all
         @tools/test-wrapper-gypbuild.py $(TESTJOBS) --outdir=$(OUTDIR) \
             --arch=$(shell echo $(DEFAULT_ARCHES) | sed -e 's/ /,/g') \
             $(TESTFLAGS)
 
 $(addsuffix .check,$(MODES)): $$(basename $$@)
         @tools/test-wrapper-gypbuild.py $(TESTJOBS) --outdir=$(OUTDIR) \
             --mode=$(basename $@) $(TESTFLAGS)
@@ skipping 30 matching lines @@
         find $(OUTDIR) -regex '.*\(host\|target\).$(basename $@)\.mk' -delete
 
 native.clean:
         rm -f $(OUTDIR)/Makefile.native
         rm -rf $(OUTDIR)/native
         find $(OUTDIR) -regex '.*\(host\|target\).native\.mk' -delete
 
 clean: $(addsuffix .clean, $(ARCHES) $(ANDROID_ARCHES)) native.clean
 
 # GYP file generation targets.
-MAKEFILES = $(addprefix $(OUTDIR)/Makefile.,$(ARCHES))
-$(MAKEFILES): $(GYPFILES) $(ENVFILE)
+OUT_MAKEFILES = $(addprefix $(OUTDIR)/Makefile.,$(ARCHES))
+$(OUT_MAKEFILES): $(GYPFILES) $(ENVFILE)
         GYP_GENERATORS=make \
         build/gyp/gyp --generator-output="$(OUTDIR)" build/all.gyp \
                       -Ibuild/standalone.gypi --depth=. \
                       -Dv8_target_arch=$(subst .,,$(suffix $@)) \
                       -S.$(subst .,,$(suffix $@)) $(GYPFLAGS)
 
 $(OUTDIR)/Makefile.native: $(GYPFILES) $(ENVFILE)
         GYP_GENERATORS=make \
         build/gyp/gyp --generator-output="$(OUTDIR)" build/all.gyp \
                       -Ibuild/standalone.gypi --depth=. -S.native $(GYPFLAGS)
@@ skipping 12 matching lines @@
 
 # Stores current GYPFLAGS in a file.
 $(ENVFILE).new:
         @mkdir -p $(OUTDIR); echo "GYPFLAGS=$(GYPFLAGS)" > $(ENVFILE).new; \
             echo "CXX=$(CXX)" >> $(ENVFILE).new
 
 # Dependencies.
 dependencies:
         svn checkout --force http://gyp.googlecode.com/svn/trunk build/gyp \
             --revision 1282