Use address-taken to disambiguate global variable and indirect memops.

 Major steps include:
 1). introduces a not-addr-taken bit-field in GlobalVariable
 2). GlobalOpt pass sets "not-address-taken" if it proves a global varirable 
    dosen't have its address taken.
 3). AA use this info for disambiguation. 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193251 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 74c0ea4..9b5fb27 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -704,7 +704,7 @@
                            unsigned Linkage, bool HasLinkage,
                            unsigned Visibility) {
   unsigned AddrSpace;
-  bool IsConstant, UnnamedAddr, IsExternallyInitialized;
+  bool IsConstant, UnnamedAddr, IsExternallyInitialized, notAddrTaken;
   GlobalVariable::ThreadLocalMode TLM;
   LocTy UnnamedAddrLoc;
   LocTy IsExternallyInitializedLoc;
@@ -719,6 +719,7 @@
                          IsExternallyInitialized,
                          &IsExternallyInitializedLoc) ||
       ParseGlobalType(IsConstant) ||
+      ParseOptionalToken(lltok::kw_notaddrtaken, notAddrTaken) ||
       ParseType(Ty, TyLoc))
     return true;
 
@@ -776,6 +777,7 @@
   GV->setLinkage((GlobalValue::LinkageTypes)Linkage);
   GV->setVisibility((GlobalValue::VisibilityTypes)Visibility);
   GV->setExternallyInitialized(IsExternallyInitialized);
+  GV->setAddressMaybeTaken(!notAddrTaken);
   GV->setThreadLocalMode(TLM);
   GV->setUnnamedAddr(UnnamedAddr);