Simplify the methods for creating a pointer, reference, member-pointer,

or block-pointer type by removing the qualifiers parameter.  Introduce a
method to perform semantic checking when adding qualifiers to a type.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@105526 91177308-0d34-0410-b5e6-96231b3b80d8