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/tools/llvm-cxxdump/Error.cpp b/llvm/tools/llvm-cxxdump/Error.cpp
index ff9f0f5..d59547e 100644
--- a/llvm/tools/llvm-cxxdump/Error.cpp
+++ b/llvm/tools/llvm-cxxdump/Error.cpp
@@ -22,7 +22,7 @@
 // deal with the Error value directly, rather than converting to error_code.
 class cxxdump_error_category : public std::error_category {
 public:
-  const char *name() const LLVM_NOEXCEPT override { return "llvm.cxxdump"; }
+  const char *name() const noexcept override { return "llvm.cxxdump"; }
   std::string message(int ev) const override {
     switch (static_cast<cxxdump_error>(ev)) {
     case cxxdump_error::success: