[x86] Switch some of the new consolidated vector tests to use
a bare-metal triple and have nice BB labels, etc.

No significant change here, just tidying up to have a consistent set of
OS-agnostic vector functionality here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218854 91177308-0d34-0410-b5e6-96231b3b80d8
[x86] Add a comment clarifying that this test should span all manners of
generic DAG combining of shuffles relevant to x86.

My plan is to fold a bunch of the other DAG combining test cases into
this one, while converting them to use the nice new FileCheck assertion
syntax.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218855 91177308-0d34-0410-b5e6-96231b3b80d8
[x86] Minimize the parameters to this test for clarity.

The test has to do with DAG combines, and so it doesn't need the new
vector shuffle lowering to be effective. Also, it has a nice in-IR
triple string which we should really be using rather than command line
flags (unless it varies form RUN-line to RUN-line). Finally, I much
prefer letting LLVM synthesize the correct datalayout string from the
triple rather than baking one in here that will just become stale.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218856 91177308-0d34-0410-b5e6-96231b3b80d8
[x86] Update this test to run a full complement of the ISA extensions,
and use the new grouped FileCheck patterns to match them.

No interesting changes yet, but this test is now in proper form to have
the other shuffle combining tests merged into it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218857 91177308-0d34-0410-b5e6-96231b3b80d8
[x86] Merge the bitwise operation shuffle combining into the common test
file, adding assertions across the ISA variants for it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218858 91177308-0d34-0410-b5e6-96231b3b80d8
[x86] Merge the second set of vector combining tests into a common test
file.

Some of these really don't make sense to test -- we're testing for the
*lack* of combining two shuffles into one, presumably because the two
would generate better shuffles in the end. But if you look at the
generated code shown here, in many cases the generated code is, frankly,
terrible. Or we combine any two generated shuffles back into a single
instruction! I've left a FIXME to revisit these decisions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218859 91177308-0d34-0410-b5e6-96231b3b80d8