Support for SDIV and MLS ARM instructions, and implement DoModI using them

build/common.gypi

Index: build/common.gypi
===================================================================
--- build/common.gypi	(revision 12559)
+++ build/common.gypi	(working copy)
@@ -43,6 +43,11 @@
     # access is allowed for all CPUs.
     'v8_can_use_unaligned_accesses%': 'default',
 
+    # Setting 'v8_can_use_integer_division' to 'true' will allow the code
+    # generated by V8 to utilize hardware integer division instruction
+    # Setting it to 'false' will not use hardware integer division instruction
+    'v8_can_use_integer_division%': 'true',

[danno, 2012/09/27 15:28:09]

I think this flag is mis-named. can_use_sdiv_instructions or something similar
is better, since flags expressing similar functionality (VFP) clearly reference
something that is ARM-specific.

also, I we can't land this in the current form as a compile-time flag, since
there is only one binary that gets distributed on ARM

+
     # Setting 'v8_can_use_vfp2_instructions' to 'true' will enable use of ARM VFP
     # instructions in the V8 generated code. VFP instructions will be enabled
     # both for the snapshot and for the ARM target. Leaving the default value
@@ -139,6 +144,16 @@
               'CAN_USE_UNALIGNED_ACCESSES=0',
             ],
           }],
+          [ 'v8_can_use_integer_division=="true"', {
+            'defines': [
+              'CAN_USE_INTEGER_DIVISION=1',
+            ],
+          }],
+          [ 'v8_can_use_integer_division=="false"', {
+            'defines': [
+              'CAN_USE_INTEGER_DIVISION=0',
+            ],
+          }],
           [ 'v8_can_use_vfp2_instructions=="true"', {
             'defines': [
               'CAN_USE_VFP2_INSTRUCTIONS',