Correct parameter in comment for NewConsString

This commit changes the pararmeter names in the comment for
NewConsString which currently do not match the actual parameter names in
the function definition or the declaration in code-stub-assembler.cc.

Bug: 
Change-Id: I162a2027cc37512de8a09e520a1fb13c9445fa97
Reviewed-on: https://chromium-review.googlesource.com/657017Reviewed-by: Daniel Clifford <danno@chromium.org>
Commit-Queue: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48964}

src/code-stub-assembler.h

@@ -720,7 +720,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                                   AllocationFlags flags = kNone);
 
   // Allocate an appropriate one- or two-byte ConsString with the first and
-  // second parts specified by |first| and |second|.
+  // second parts specified by |left| and |right|.
   Node* NewConsString(Node* context, Node* length, Node* left, Node* right,
                       AllocationFlags flags = kNone);