A64: Remove temporary sxtw instructions

src/a64/macro-assembler-a64.cc

Index: src/a64/macro-assembler-a64.cc
diff --git a/src/a64/macro-assembler-a64.cc b/src/a64/macro-assembler-a64.cc
index 41930a3230193522c29cc34b956f066a8b870410..25edc06161dc533d02e718cc09d9fe4fc4312cda 100644
--- a/src/a64/macro-assembler-a64.cc
+++ b/src/a64/macro-assembler-a64.cc
@@ -2824,10 +2824,6 @@ void MacroAssembler::TruncateDoubleToI(Register result,
   Pop(lr);
 
   Bind(&done);
-
-  // TODO(rmcilroy): Remove this Sxtw once the following bug is fixed:
-  // https://code.google.com/p/v8/issues/detail?id=3149
-  Sxtw(result, result.W());
 }
 
 
@@ -2854,10 +2850,6 @@ void MacroAssembler::TruncateHeapNumberToI(Register result,
   Pop(lr);
 
   Bind(&done);
-
-  // TODO(rmcilroy): Remove this Sxtw once the following bug is fixed:
-  // https://code.google.com/p/v8/issues/detail?id=3149
-  Sxtw(result, result.W());
 }