Move ref qualifiers from Type bitfields into FunctionProtoType, stealing two

bits from the number of parameters. This brings the bitfields down from 33 bits
to 32 bits, reducing the size of Types by 4 bytes on 32-bit systems.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@171827 91177308-0d34-0410-b5e6-96231b3b80d8