In the final step for preserving typedef info better in the AST, upgrade

In the final step for preserving typedef info better in the AST, upgrade
isPointerType and isVectorType to only look through a single level of typedef
when one is present.  For this invalid code:

typedef float float4 __attribute__((vector_size(16)));
typedef int int4 __attribute__((vector_size(16)));
typedef int4* int4p;
void test(float4 a, int4p result, int i) {
    result[i] = a;
}

we now get:

t.c:5:15: error: incompatible types assigning 'float4' to 'int4'
    result[i] = a;
    ~~~~~~~~~ ^ ~

instead of:

t.c:5:15: error: incompatible types assigning 'float4' to 'int  __attribute__((vector_size(16)))'
    result[i] = a;
    ~~~~~~~~~ ^ ~

The rest of the type predicates should be upgraded to do the same thing.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@39932 91177308-0d34-0410-b5e6-96231b3b80d8