Heap::AllocateStringFromOneByte() and major part of its callers handlified.

src/jsregexp.h

Index: src/jsregexp.h
diff --git a/src/jsregexp.h b/src/jsregexp.h
index a0b526b6141c8d6dfdd0ee30ce87cd45d904cbff..444c66f812f954bbac0f54218102209158048181 100644
--- a/src/jsregexp.h
+++ b/src/jsregexp.h
@@ -69,9 +69,10 @@ class RegExpImpl {
   // generic data and choice of implementation - as well as what
   // the implementation wants to store in the data field.
   // Returns false if compilation fails.
-  static Handle<Object> Compile(Handle<JSRegExp> re,
-                                Handle<String> pattern,
-                                Handle<String> flags);
+  MUST_USE_RESULT static MaybeHandle<Object> Compile(
+      Handle<JSRegExp> re,
+      Handle<String> pattern,
+      Handle<String> flags);
 
   // See ECMA-262 section 15.10.6.2.
   // This function calls the garbage collector if necessary.