WebCLRestrictor::check3dImageParameter: updated for image3d_t from new clang (not a pointer)

This means 3d-images.cl should now pass. And it does pass when
executed from command line, but the test suite returns an error?!
squash! Disabled a fragment of code for rewriting records

Handle difference in casting from clang::TypeLoc to clang::FunctionTypeLoc
lit.site.cfg.in: disable pipefail

We only care about the (ie.) FileCheck result, not all the intermediate
parts of the pipeline.
image2d-type-as-argument: split test into two parts for clang3.4

Clang3.4 now catches more errors which prevents it from getting to the
WebCL validator phase. Now the new errors from clang are triggered in
the first part of the test and the WebCL-specific errors in the
second, allowing both errors to be tested.
TypeAccessChecker::validateParmVarAccess: argument type is now clang::ParmVarDecl&

It used to be clang::ValueDecl& although it was known by the caller
it's also clang::ParmVarDecl&.
squash! Disabled image2d_t access control related code that doesn't compile with Clang 3.4

Use the Clang3.4 interface for accessing declaration attributes (image
qualifiers). Not perfect yet, though, as there is a part where the
original logic seemed fishy..
read-image, read-image-address-none: don't use CLK_* sampler_t as argument

Instead sampler_t can only by constructed during the initialization of
a sampler_t value. Clang currently prevents constructing values of
type sampler_t otherwise, so it is sufficient to check that the
initialization is safe.
sampler-type-errors?.cl: clang now handles certain errors before wcl pass

Moved tests to separate passes so that all errors get properly
generated, otherwise processing my stop early. The first pass includes
only clang-generated errors.
sampler-type-transformations: removed transformations that cannot occur

The transformations for read_image parameters cannot happen currently,
as they are flagged as errors by Clang.
unsupported-builtin-as-kernel-arg: the format of error messages has changed

Clang has changed the format of the error messages; updated test case
accordingly.