[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/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index d728f1a..c6406e4 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -3082,12 +3082,12 @@
 }
 
 PreservedAnalyses InstCombinePass::run(Function &F,
-                                       AnalysisManager<Function> *AM) {
-  auto &AC = AM->getResult<AssumptionAnalysis>(F);
-  auto &DT = AM->getResult<DominatorTreeAnalysis>(F);
-  auto &TLI = AM->getResult<TargetLibraryAnalysis>(F);
+                                       AnalysisManager<Function> &AM) {
+  auto &AC = AM.getResult<AssumptionAnalysis>(F);
+  auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
+  auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
 
-  auto *LI = AM->getCachedResult<LoopAnalysis>(F);
+  auto *LI = AM.getCachedResult<LoopAnalysis>(F);
 
   // FIXME: The AliasAnalysis is not yet supported in the new pass manager
   if (!combineInstructionsOverFunction(F, Worklist, nullptr, AC, TLI, DT,