Reland of [turbofan] ARM: Implement vswp and use in gap resolver

src/arm/assembler-arm.h

Index: src/arm/assembler-arm.h
diff --git a/src/arm/assembler-arm.h b/src/arm/assembler-arm.h
index 7a9e8bde3bdc29eb4e0bbb2882086d56f644dad3..83afcae2788794175c8d05a96f1265c5d3c64836 100644
--- a/src/arm/assembler-arm.h
+++ b/src/arm/assembler-arm.h
@@ -1303,8 +1303,8 @@ class Assembler : public AssemblerBase {
               const Condition cond = al);
 
   // Support for NEON.
-  // All these APIs support D0 to D31 and Q0 to Q15.
 
+  // All these APIs support D0 to D31 and Q0 to Q15.
   void vld1(NeonSize size,
             const NeonListOperand& dst,
             const NeonMemOperand& src);
@@ -1313,6 +1313,9 @@ class Assembler : public AssemblerBase {
             const NeonMemOperand& dst);
   void vmovl(NeonDataType dt, QwNeonRegister dst, DwVfpRegister src);
 
+  // Currently, vswp supports only D0 to D31.
+  void vswp(DwVfpRegister srcdst0, DwVfpRegister srcdst1);
+
   // Pseudo instructions
 
   // Different nop operations are used by the code generator to detect certain