Remove _mesa_is_type_integer and _mesa_is_enum_format_or_type_integer

Remove _mesa_is_type_integer and _mesa_is_enum_format_or_type_integer

The comment for _mesa_is_type_integer is confusing because it says that it
returns whether the type is an “integer (non-normalized)” format. I don't
think it makes sense to say whether a type is normalized or not because it
depends on what format it is used with. For example, GL_RGBA+GL_UNSIGNED_BYTE
is normalized but GL_RGBA_INTEGER+GL_UNSIGNED_BYTE isn't. If the normalized
comment is just a mistake then it still doesn't make much sense because it is
missing the packed-pixel types such as GL_UNSIGNED_INT_5_6_5. If those were
added then it effectively just returns type != GL_FLOAT.

That function was only used in _mesa_is_enum_format_or_type_integer. This
function effectively checks whether the format is non-normalized or the type
is an integer. I can't think of any situation where that check would make
sense.

As far as I can tell neither of these functions have ever been used anywhere
so we should just remove them to avoid confusion.

These functions were added in 9ad8f431b2a47060bf05517246ab0fa8d249c800.

Reviewed-by: Brian Paul <brianp@vmware.com>