Add cortex-m3 CPU to getCPUDefineSuffix mapping.
Patch by Sylvère Teissier.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@122965 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index f5fb08a..16a1260 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -1811,6 +1811,7 @@
       .Cases("arm1136jf-s", "mpcorenovfp", "mpcore", "6K")
       .Cases("arm1156t2-s", "arm1156t2f-s", "6T2")
       .Cases("cortex-a8", "cortex-a9", "7A")
+      .Case("cortex-m3", "7M")
       .Default(0);
   }
   virtual bool setCPU(const std::string &Name) {