Make some constants' meaning clear for X64

src/x64/assembler-x64.cc

Index: src/x64/assembler-x64.cc
diff --git a/src/x64/assembler-x64.cc b/src/x64/assembler-x64.cc
index f5939c3b7e1f1604d18528fe2cdd5d9481061132..8969d89a6a75db3b8a021ea666db81cffb4c9033 100644
--- a/src/x64/assembler-x64.cc
+++ b/src/x64/assembler-x64.cc
@@ -164,10 +164,7 @@ void CpuFeatures::Probe() {
 // Patch the code at the current PC with a call to the target address.
 // Additional guard int3 instructions can be added if required.
 void RelocInfo::PatchCodeWithCall(Address target, int guard_bytes) {
-  // Load register with immediate 64 and call through a register instructions
-  // takes up 13 bytes and int3 takes up one byte.
-  static const int kCallCodeSize = 13;
-  int code_size = kCallCodeSize + guard_bytes;
+  int code_size = Assembler::kCallSequenceLength + guard_bytes;
 
   // Create a code patcher.
   CodePatcher patcher(pc_, code_size);
@@ -183,7 +180,7 @@ void RelocInfo::PatchCodeWithCall(Address target, int guard_bytes) {
   patcher.masm()->call(r10);
 
   // Check that the size of the code generated is as expected.
-  ASSERT_EQ(kCallCodeSize,
+  ASSERT_EQ(Assembler::kCallSequenceLength,
             patcher.masm()->SizeOfCodeGeneratedSince(&check_codesize));
 
   // Add the requested number of int3 instructions after the call.