Instead of storing an ASTContext* in FunctionProtoTypes with computed noexcept specifiers, unique FunctionProtoTypes with a ContextualFoldingSet, as suggested by John McCall.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127568 91177308-0d34-0410-b5e6-96231b3b80d8
13 files changed