No bug - Fix comments to match code. DONTBUILD

This code has been moved around several times, but it originated in bug 995704. Comments 20 and later indicate that the value was changed from 1k to 4k per review, and the code comments weren't updated.

MozReview-Commit-ID: JQjoWq1jGF9

--HG--
extra : rebase_source : f91924693645aef2d003692c8749c996d812d9fc
extra : amend_source : 9cb57f677acd1d61c78f8297d0136b6ab2f09b26

js/src/jit/x64/MacroAssembler-x64.cpp

@@ -424,7 +424,7 @@ MacroAssembler::subFromStackPtr(Imm32 imm32)
         // On windows, we cannot skip very far down the stack without touching the
         // memory pages in-between.  This is a corner-case code for situations where the
         // Ion frame data for a piece of code is very large.  To handle this special case,
-        // for frames over 1k in size we allocate memory on the stack incrementally, touching
+        // for frames over 4k in size we allocate memory on the stack incrementally, touching
         // it as we go.
         //
         // When the amount is quite large, which it can be, we emit an actual loop, in order

js/src/jit/x86/MacroAssembler-x86.cpp

@@ -331,7 +331,7 @@ MacroAssembler::subFromStackPtr(Imm32 imm32)
         // On windows, we cannot skip very far down the stack without touching the
         // memory pages in-between.  This is a corner-case code for situations where the
         // Ion frame data for a piece of code is very large.  To handle this special case,
-        // for frames over 1k in size we allocate memory on the stack incrementally, touching
+        // for frames over 4k in size we allocate memory on the stack incrementally, touching
         // it as we go.
         //
         // When the amount is quite large, which it can be, we emit an actual loop, in order