PR4795: Remove EEVT::isFP, isInt and isVec types used by TableGen's type

PR4795: Remove EEVT::isFP, isInt and isVec types used by TableGen's type
inferencing.  As far as I can tell, these are equivalent to the existing
MVT::fAny, iAny and vAny types, and having both of them makes it harder
to reason about and modify the type inferencing code.

The specific problem in PR4795 occurs when updating a vAny type to be fAny
or iAny, or vice versa.  Both iAny and fAny include vector types -- they
intersect with the set of types represented by vAny.  When merging them,
choose fAny/iAny to represent the intersection.  This is not perfect, since
fAny/iAny also include scalar types, but it is good enough for TableGen's
type inferencing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80423 91177308-0d34-0410-b5e6-96231b3b80d8