When determining the attribute's parsed kind, pay attention to the syntax used. This fixes bugs where an attribute has differing GNU and Declspec spellings, but they are treated as the same. Eg) __declspec(aligned) when it should be __attribute__((aligned)), and __attribute__((align)) when it should be __declspec(align).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@199144 91177308-0d34-0410-b5e6-96231b3b80d8