Fix issues with Arm's use of embedded constant pools

src/x87/assembler-x87.h

Index: src/x87/assembler-x87.h
diff --git a/src/x87/assembler-x87.h b/src/x87/assembler-x87.h
index ea05ab975f03c02eb37a195606d6c7c8ae46c12b..ededc2aadc53d2fa00cab4fccad672db2647dfcf 100644
--- a/src/x87/assembler-x87.h
+++ b/src/x87/assembler-x87.h
@@ -590,6 +590,9 @@ class Assembler : public AssemblerBase {
   // possible to align the pc offset to a multiple
   // of m. m must be a power of 2.
   void Align(int m);
+  // Insert the smallest number of zero bytes possible to align the pc offset
+  // to a mulitple of m. m must be a power of 2 (>= 2).
+  void DataAlign(int m);
   void Nop(int bytes = 1);
   // Aligns code to something that's optimal for a jump target for the platform.
   void CodeTargetAlign();