Extend the IL for selecting TLS models (PR9788)

This allows the user/front-end to specify a model that is better
than what LLVM would choose by default. For example, a variable
might be declared as

  @x = thread_local(initialexec) global i32 42

if it will not be used in a shared library that is dlopen'ed.

If the specified model isn't supported by the target, or if LLVM can
make a better choice, a different model may be used.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159077 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index 7293f3d..afba2e8 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -684,7 +684,7 @@
   GlobalVariable *NG =
     new GlobalVariable(*DstGV->getParent(), NewType, SrcGV->isConstant(),
                        DstGV->getLinkage(), /*init*/0, /*name*/"", DstGV,
-                       DstGV->isThreadLocal(),
+                       DstGV->getThreadLocalMode(),
                        DstGV->getType()->getAddressSpace());
   
   // Propagate alignment, visibility and section info.
@@ -759,7 +759,7 @@
     new GlobalVariable(*DstM, TypeMap.get(SGV->getType()->getElementType()),
                        SGV->isConstant(), SGV->getLinkage(), /*init*/0,
                        SGV->getName(), /*insertbefore*/0,
-                       SGV->isThreadLocal(),
+                       SGV->getThreadLocalMode(),
                        SGV->getType()->getAddressSpace());
   // Propagate alignment, visibility and section info.
   copyGVAttributes(NewDGV, SGV);