Rename some GC classes so that their roll will hopefully be clearer.

In particular, Collector was confusing to implementors. Several
thought that this compile-time class was the place to implement
their runtime GC heap. Of course, it doesn't even exist at runtime.
Specifically, the renames are:

  Collector               -> GCStrategy
  CollectorMetadata       -> GCFunctionInfo
  CollectorModuleMetadata -> GCModuleInfo
  CollectorRegistry       -> GCRegistry
  Function::getCollector  -> getGC (setGC, hasGC, clearGC)

Several accessors and nested types have also been renamed to be
consistent. These changes should be obvious.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54899 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/CodeGen/Passes.h b/include/llvm/CodeGen/Passes.h
index 412e9e3..ff1f505 100644
--- a/include/llvm/CodeGen/Passes.h
+++ b/include/llvm/CodeGen/Passes.h
@@ -152,7 +152,7 @@
   FunctionPass *getRegisterAllocator(TargetMachine &T);
 
   /// IntrinsicLowering Pass - Performs target-independent LLVM IR
-  /// transformations for highly portable collectors.
+  /// transformations for highly portable strategies.
   FunctionPass *createGCLoweringPass();
   
   /// MachineCodeAnalysis Pass - Target-independent pass to mark safe points in
@@ -161,13 +161,13 @@
   /// folding).
   FunctionPass *createGCMachineCodeAnalysisPass();
   
-  /// Deleter Pass - Releases collector metadata.
+  /// Deleter Pass - Releases GC metadata.
   /// 
-  FunctionPass *createCollectorMetadataDeleter();
+  FunctionPass *createGCInfoDeleter();
   
-  /// Creates a pass to print collector metadata.
+  /// Creates a pass to print GC metadata.
   /// 
-  FunctionPass *createCollectorMetadataPrinter(std::ostream &OS);
+  FunctionPass *createGCInfoPrinter(std::ostream &OS);
   
   /// createMachineLICMPass - This pass performs LICM on machine instructions.
   ///