Fix issues with Arm's use of embedded constant pools

src/arm/assembler-arm.cc

Index: src/arm/assembler-arm.cc
diff --git a/src/arm/assembler-arm.cc b/src/arm/assembler-arm.cc
index ed8664a9c5f32f10ddc131ad8973e2b79cc37347..75d5699785df7aecff52269d4ec34ccd42ded24b 100644
--- a/src/arm/assembler-arm.cc
+++ b/src/arm/assembler-arm.cc
@@ -494,6 +494,11 @@ void Assembler::GetCode(CodeDesc* desc) {
 
 void Assembler::Align(int m) {
   DCHECK(m >= 4 && base::bits::IsPowerOfTwo32(m));
+  // First ensure instruction alignment
+  while (pc_offset() & (kInstrSize - 1)) {
+    db(0);
+  }

[rmcilroy, 2015/06/08 11:11:10]

I'm not keen on adding this to Align since it makes it possible to insert
non-instructions into the bytestream if something goes wrong with alignment.
Instead, please add a different DataAlign() function (if you could also add a
DCHECK here that pc_offset() is 4 byte aligned that would be great).

[MTBrandyberry, 2015/06/08 13:52:39]

Done.

+  // Then pad to requested alignedment with nops
   while ((pc_offset() & (m - 1)) != 0) {
     nop();
   }