Remove LLVM_NOEXCEPT and replace it with noexcept

Now that we have dropped MSVC 2013, all supported compilers support
noexcept and we can drop this portability macro.

llvm-svn: 284672
diff --git a/llvm/lib/DebugInfo/PDB/Raw/RawError.cpp b/llvm/lib/DebugInfo/PDB/Raw/RawError.cpp
index cbce890..f4a5057 100644
--- a/llvm/lib/DebugInfo/PDB/Raw/RawError.cpp
+++ b/llvm/lib/DebugInfo/PDB/Raw/RawError.cpp
@@ -11,7 +11,7 @@
 // deal with the Error value directly, rather than converting to error_code.
 class RawErrorCategory : public std::error_category {
 public:
-  const char *name() const LLVM_NOEXCEPT override { return "llvm.pdb.raw"; }
+  const char *name() const noexcept override { return "llvm.pdb.raw"; }
 
   std::string message(int Condition) const override {
     switch (static_cast<raw_error_code>(Condition)) {