Introduce regexp=interpreted to GYP to enable building with interpreted regexp engine.

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 77 matching lines @@
   GYPFLAGS += -Dwerror=''
 endif
 # presubmit=no
 ifeq ($(presubmit), no)
   TESTFLAGS += --no-presubmit
 endif
 # strictaliasing=off (workaround for GCC-4.5)
 ifeq ($(strictaliasing), off)
   GYPFLAGS += -Dv8_no_strict_aliasing=1
 endif
+# regexp=interpreted
+ifeq ($(regexp), interpreted)
+  GYPFLAGS += -Dv8_interpreted_regexp=1
+endif
 
 # ----------------- available targets: --------------------
 # - "dependencies": pulls in external dependencies (currently: GYP)
 # - any arch listed in ARCHES (see below)
 # - any mode listed in MODES
 # - every combination <arch>.<mode>, e.g. "ia32.release"
 # - "native": current host's architecture, release mode
 # - any of the above with .check appended, e.g. "ia32.release.check"
 # - "android": cross-compile for Android/ARM (release mode)
 # - default (no target specified): build all DEFAULT_ARCHES and MODES
@@ skipping 139 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