Remove the AliasAnalysis::getMustAliases method, which is dead.

The hasNoModRefInfoForCalls isn't worth it as a filter because 
basicaa provides m/r info and everything chains to it, so remove
it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89599 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/IPA/GlobalsModRef.cpp

@@ -111,7 +111,6 @@ namespace {
     ModRefResult getModRefInfo(CallSite CS1, CallSite CS2) {
       return AliasAnalysis::getModRefInfo(CS1,CS2);
     }
-    bool hasNoModRefInfoForCalls() const { return false; }
 
     /// getModRefBehavior - Return the behavior of the specified function if
     /// called from the specified call site.  The call site may be null in which