AVX-512: gather-scatter tests; added foldable instructions;
Specify GATHER/SCATTER as heavy instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189736 91177308-0d34-0410-b5e6-96231b3b80d8
Add a clang-format file so that the tool can automatically detect the
correct style for the LLVM tree as well as projects checked out under
projects and tools.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189737 91177308-0d34-0410-b5e6-96231b3b80d8
AVX-512: updated the list of high-latency instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189740 91177308-0d34-0410-b5e6-96231b3b80d8
Create BEXTR instructions for (and ((sra or srl) x, imm), (2**size - 1)). Fixes PR17028.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189742 91177308-0d34-0410-b5e6-96231b3b80d8