1) Enforce C99 6.7.3p2: "Types other than pointer types derived from

1) Enforce C99 6.7.3p2: "Types other than pointer types derived from
object or incomplete types shall not be restrict-qualified."

2) Warn about qualifiers on function types: C99 6.7.3p8: "If the
specification of a function type includes any type qualifiers, the
behavior is undefined."

3) Implement restrict on C++ references.

4) fix some locations for various C++ reference diagnostics.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@49081 91177308-0d34-0410-b5e6-96231b3b80d8