[llvm] r191287 - [msan] Handling of atomic load/store, atomic rmw, cmpxchg.

[Johannes Obermayr]

This commit introduces following build error on openSUSE:

lib/Transforms/Instrumentation/MemorySanitizer.cpp: In member function 'llvm::AtomicOrdering {anonymous}::MemorySanitizerVisitor::addAcquireOrdering(llvm::AtomicOrdering)':
lib/Transforms/Instrumentation/MemorySanitizer.cpp:937:3: warning: control reaches end of non-void function [-Wreturn-type]
lib/Transforms/Instrumentation/MemorySanitizer.cpp: In member function 'llvm::AtomicOrdering {anonymous}::MemorySanitizerVisitor::addReleaseOrdering(llvm::AtomicOrdering)':
lib/Transforms/Instrumentation/MemorySanitizer.cpp:921:3: warning: control reaches end of non-void function [-Wreturn-type]

... testing for serious compiler warnings
I: Program returns random data in a function
E: llvm no-return-in-nonvoid-function /home/abuild/rpmbuild/BUILD/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp:937, 921

Please add a return value in default: switch or after switch{}.