Fix race condition in jump table list creation

src/IceGlobalContext.h

 //===- subzero/src/IceGlobalContext.h - Global context defs -----*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 199 matching lines @@
   /// getConstantPool() returns a copy of the constant pool for constants of a
   /// given type.
   ConstantList getConstantPool(Type Ty);
   /// Returns a copy of the list of external symbols.
   ConstantList getConstantExternSyms();
   /// @}
 
   /// Return a locked pointer to the registered jump tables.
   JumpTableDataList getJumpTables();
   /// Create a new jump table entry and return a reference to it.
-  JumpTableData &addJumpTable(IceString FuncName, SizeT Id, SizeT NumTargets);
+  JumpTableData &addJumpTable(IceString FuncName, SizeT Id,
+                              const JumpTableData::TargetList &TargetList);
 
   const ClFlags &getFlags() const { return Flags; }
 
   bool isIRGenerationDisabled() const {
     return getFlags().getDisableIRGeneration();
   }
 
   /// Allocate data of type T using the global allocator. We allow entities
   /// allocated from this global allocator to be either trivially or
   /// non-trivially destructible. We optimize the case when T is trivially
@@ skipping 370 matching lines @@
   explicit OstreamLocker(GlobalContext *Ctx) : Ctx(Ctx) { Ctx->lockStr(); }
   ~OstreamLocker() { Ctx->unlockStr(); }
 
 private:
   GlobalContext *const Ctx;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEGLOBALCONTEXT_H