[CallSite removal] Migrate all Alias Analysis APIs to use the newly
minted `CallBase` class instead of the `CallSite` wrapper.

This moves the largest interwoven collection of APIs that traffic in
`CallSite`s. While a handful of these could have been migrated with
a minorly more shallow migration by converting from a `CallSite` to
a `CallBase`, it hardly seemed worth it. Most of the APIs needed to
migrate together because of the complex interplay of AA APIs and the
fact that converting from a `CallBase` to a `CallSite` isn't free in its
current implementation.

Out of tree users of these APIs can fairly reliably migrate with some
combination of `.getInstruction()` on the `CallSite` instance and
casting the resulting pointer. The most generic form will look like `CS`
-> `cast_or_null<CallBase>(CS.getInstruction())` but in most cases there
is a more elegant migration. Hopefully, this migrates enough APIs for
users to fully move from `CallSite` to the base class. All of the
in-tree users were easily migrated in that fashion.

Thanks for the review from Saleem!

Differential Revision: https://reviews.llvm.org/D55641

llvm-svn: 350503
diff --git a/llvm/lib/Analysis/ScopedNoAliasAA.cpp b/llvm/lib/Analysis/ScopedNoAliasAA.cpp
index f12275a..9a581fe 100644
--- a/llvm/lib/Analysis/ScopedNoAliasAA.cpp
+++ b/llvm/lib/Analysis/ScopedNoAliasAA.cpp
@@ -95,39 +95,36 @@
   return AAResultBase::alias(LocA, LocB);
 }
 
-ModRefInfo ScopedNoAliasAAResult::getModRefInfo(ImmutableCallSite CS,
+ModRefInfo ScopedNoAliasAAResult::getModRefInfo(const CallBase *Call,
                                                 const MemoryLocation &Loc) {
   if (!EnableScopedNoAlias)
-    return AAResultBase::getModRefInfo(CS, Loc);
+    return AAResultBase::getModRefInfo(Call, Loc);
 
-  if (!mayAliasInScopes(Loc.AATags.Scope, CS.getInstruction()->getMetadata(
-                                              LLVMContext::MD_noalias)))
+  if (!mayAliasInScopes(Loc.AATags.Scope,
+                        Call->getMetadata(LLVMContext::MD_noalias)))
     return ModRefInfo::NoModRef;
 
-  if (!mayAliasInScopes(
-          CS.getInstruction()->getMetadata(LLVMContext::MD_alias_scope),
-          Loc.AATags.NoAlias))
+  if (!mayAliasInScopes(Call->getMetadata(LLVMContext::MD_alias_scope),
+                        Loc.AATags.NoAlias))
     return ModRefInfo::NoModRef;
 
-  return AAResultBase::getModRefInfo(CS, Loc);
+  return AAResultBase::getModRefInfo(Call, Loc);
 }
 
-ModRefInfo ScopedNoAliasAAResult::getModRefInfo(ImmutableCallSite CS1,
-                                                ImmutableCallSite CS2) {
+ModRefInfo ScopedNoAliasAAResult::getModRefInfo(const CallBase *Call1,
+                                                const CallBase *Call2) {
   if (!EnableScopedNoAlias)
-    return AAResultBase::getModRefInfo(CS1, CS2);
+    return AAResultBase::getModRefInfo(Call1, Call2);
 
-  if (!mayAliasInScopes(
-          CS1.getInstruction()->getMetadata(LLVMContext::MD_alias_scope),
-          CS2.getInstruction()->getMetadata(LLVMContext::MD_noalias)))
+  if (!mayAliasInScopes(Call1->getMetadata(LLVMContext::MD_alias_scope),
+                        Call2->getMetadata(LLVMContext::MD_noalias)))
     return ModRefInfo::NoModRef;
 
-  if (!mayAliasInScopes(
-          CS2.getInstruction()->getMetadata(LLVMContext::MD_alias_scope),
-          CS1.getInstruction()->getMetadata(LLVMContext::MD_noalias)))
+  if (!mayAliasInScopes(Call2->getMetadata(LLVMContext::MD_alias_scope),
+                        Call1->getMetadata(LLVMContext::MD_noalias)))
     return ModRefInfo::NoModRef;
 
-  return AAResultBase::getModRefInfo(CS1, CS2);
+  return AAResultBase::getModRefInfo(Call1, Call2);
 }
 
 static void collectMDInDomain(const MDNode *List, const MDNode *Domain,