Add Makefile options to build for the Raspberry Pi (armv7=0, arm_fpu=vfp2).

With these Makefile changes, it is possible to build V8 on the Raspberry Pi with the following make invocation:

make native armv7=false vfp3=off hardfp=on disassembler=on console=readline snapshot=on gdbjit=on strictaliasing=off

R=danno@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/11722003
Patch from Luis Reis <luis.m.reis@gmail.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13297 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

AUTHORS

@@ -34,6 +34,7 @@ Joel Stanley <joel.stan@gmail.com>
 John Jozwiak <jjozwiak@codeaurora.org>
 Jonathan Liu <net147@gmail.com>
 Kun Zhang <zhangk@codeaurora.org>
+Luis Reis <luis.m.reis@gmail.com>
 Martyn Capewell <martyn.capewell@arm.com>
 Mathias Bynens <mathias@qiwi.be>
 Matt Hanselman <mjhanselman@gmail.com>

Makefile

@@ -91,13 +91,13 @@ endif
 ifeq ($(vfp2), off)
   GYPFLAGS += -Dv8_can_use_vfp2_instructions=false
 else
-  GYPFLAGS += -Dv8_can_use_vfp2_instructions=true
+  GYPFLAGS += -Dv8_can_use_vfp2_instructions=true -Darm_fpu=vfpv2
 endif
 # vfp3=off
 ifeq ($(vfp3), off)
   GYPFLAGS += -Dv8_can_use_vfp3_instructions=false
 else
-  GYPFLAGS += -Dv8_can_use_vfp3_instructions=true
+  GYPFLAGS += -Dv8_can_use_vfp3_instructions=true -Darm_fpu=vfpv3
 endif
 # debuggersupport=off
 ifeq ($(debuggersupport), off)
@@ -127,6 +127,10 @@ endif
 ifeq ($(hardfp), on)
   GYPFLAGS += -Dv8_use_arm_eabi_hardfloat=true
 endif
+# armv7=false
+ifeq ($(armv7), false)
+  GYPFLAGS += -Darmv7=0
+endif
 
 # ----------------- available targets: --------------------
 # - "dependencies": pulls in external dependencies (currently: GYP)