[CMake] clangStaticAnalyzerFrontend: Deprecate LLVM_NO_RTTI.
[CMake] Put lli-child-target into the Folder "Misc".
[CMake] Let llvm_process_sources check not only *.cpp but also *.c.
[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.
[CMake] Apply -ffunction-data-sectinos not only to CMAKE_CXX_FLAGS, but also to CMAKE_C_FLAGS.
[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.