[vectorizer] Completely disable the block frequency guidance of the loop
vectorizer, placing it behind an off-by-default flag.

It turns out that block frequency isn't what we want at all, here or
elsewhere. This has been I think a nagging feeling for several of us
working with it, but Arnold has given some really nice simple examples
where the results are so comprehensively wrong that they aren't useful.

I'm planning to email the dev list with a summary of why its not really
useful and a couple of ideas about how to better structure these types
of heuristics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200294 91177308-0d34-0410-b5e6-96231b3b80d8
[CMake] Put lli-child-target into the Folder "Misc".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200297 91177308-0d34-0410-b5e6-96231b3b80d8
[CMake] Let llvm_process_sources check not only *.cpp but also *.c.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200298 91177308-0d34-0410-b5e6-96231b3b80d8
[CMake] Move -ffunction-data-sections stuff to HandleLLVMOptions.

With this tweaks, also unittests are compiled with -ffunction-sections.

It's hard to control contextual CMAKE_CXX_FLAGS. We should get rid of twiddling it as possible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200299 91177308-0d34-0410-b5e6-96231b3b80d8
[CMake] Apply -ffunction-data-sectinos not only to CMAKE_CXX_FLAGS, but also to CMAKE_C_FLAGS.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200300 91177308-0d34-0410-b5e6-96231b3b80d8
[CMake] Enhance llvm_update_compile_flags(name sources) to handle LLVM_REQUIRES_EH and LLVM_REQUIRES_RTTI.

LLVM_REQUIRES_EH implies LLVM_REQUIRES_RTTI. It is as same behavior as Makefile.rule's.
llvm/examples/ExceptionDemo is affected. (It was built with -fno-rtti.)

For MSVC, Remove flags like "/EHsc /GR" in HandleLLVMOptions, or CL.EXE complains with flags like "/GR /GR-".

llvm_update_compile_flags() updates source file property if the target contains *.c.
COMPILE_FLAGS in target properties affects both C++ and C!

LLVM_NO_RTTI is deprecated. It was introduced by me and was my mistake.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200301 91177308-0d34-0410-b5e6-96231b3b80d8
[CMake] Prune CMAKE_CXX_FLAGS stuff in llvm_process_sources.

It is the final step to deprecate contextual CMAKE_CXX_FLAGS.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200303 91177308-0d34-0410-b5e6-96231b3b80d8