[PM] Make the AnalysisManager parameter to run methods a reference.

This was originally a pointer to support pass managers which didn't use
AnalysisManagers. However, that doesn't realistically come up much and
the complexity of supporting it doesn't really make sense.

In fact, *many* parts of the pass manager were just assuming the pointer
was never null already. This at least makes it much more explicit and
clear.

llvm-svn: 263219
diff --git a/llvm/lib/Analysis/BasicAliasAnalysis.cpp b/llvm/lib/Analysis/BasicAliasAnalysis.cpp
index 84507ec..1897210 100644
--- a/llvm/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/llvm/lib/Analysis/BasicAliasAnalysis.cpp
@@ -1608,12 +1608,12 @@
 
 char BasicAA::PassID;
 
-BasicAAResult BasicAA::run(Function &F, AnalysisManager<Function> *AM) {
+BasicAAResult BasicAA::run(Function &F, AnalysisManager<Function> &AM) {
   return BasicAAResult(F.getParent()->getDataLayout(),
-                       AM->getResult<TargetLibraryAnalysis>(F),
-                       AM->getResult<AssumptionAnalysis>(F),
-                       AM->getCachedResult<DominatorTreeAnalysis>(F),
-                       AM->getCachedResult<LoopAnalysis>(F));
+                       AM.getResult<TargetLibraryAnalysis>(F),
+                       AM.getResult<AssumptionAnalysis>(F),
+                       AM.getCachedResult<DominatorTreeAnalysis>(F),
+                       AM.getCachedResult<LoopAnalysis>(F));
 }
 
 BasicAAWrapperPass::BasicAAWrapperPass() : FunctionPass(ID) {