Introduce enum values for previously defined metadata types. (NFC)

Our metadata scheme lazily assigns IDs to string metadata, but we have a mechanism to preassign them as well.  Using a preassigned ID is helpful since we get compile time type checking, and avoid some (minimal) string construction and comparison.  This change adds enum value for three existing metadata types:
+    MD_nontemporal = 9, // "nontemporal"
+    MD_mem_parallel_loop_access = 10, // "llvm.mem.parallel_loop_access"
+    MD_nonnull = 11 // "nonnull"

I went through an updated various uses as well.  I made no attempt to get all uses; I focused on the ones which were easily grepable and easily to translate.  For example, there were several items in LoopInfo.cpp I chose not to update.

llvm-svn: 220248

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 462d5b7cf0b..53f3be51665 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -2624,7 +2624,7 @@ bool llvm::isKnownNonNull(const Value *V, const TargetLibraryInfo *TLI) {
 
   // A Load tagged w/nonnull metadata is never null. 
   if (const LoadInst *LI = dyn_cast<LoadInst>(V))
-    return LI->getMetadata("nonnull");
+    return LI->getMetadata(LLVMContext::MD_nonnull);
 
   if (ImmutableCallSite CS = V)
     if (CS.isReturnNonNull())