[PATCH] Add a GCStrategy for CoreCLR

[Sanjoy Das]

Minor nit inline that can be fixed post-commit.  Otherwise I don't see any issues with this change, but I'll wait for @reames to take a look.


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Comment at: lib/Transforms/Scalar/PlaceSafepoints.cpp:509
@@ -507,2 +508,3 @@
     const std::string StatepointExampleName("statepoint-example");
-    return StatepointExampleName == F.getGC();
+    const std::string CoreCLRName("coreclr");
+    return (StatepointExampleName == FunctionGCName) ||
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In a later change, I think we can change both "statepoint-example" and "coreclr" to be `llvm::StringRef`s and not `std::string`s to avoid allocation and deallocation on each call to `shouldRewriteFunction`.

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Comment at: lib/Transforms/Scalar/RewriteStatepointsForGC.cpp:1933
@@ -1932,1 +1932,3 @@
+    const char *FunctionGCName = F.getGC();
     const std::string StatepointExampleName("statepoint-example");
+    const std::string CoreCLRName("coreclr");
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Same comment w.r.t. `std::string` vs. `llvm::StringRef` here.

http://reviews.llvm.org/D9767

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