[llvm] r200301 - [CMake] Enhance llvm_update_compile_flags(name sources) to handle LLVM_REQUIRES_EH and LLVM_REQUIRES_RTTI.

[Tim Northover]

Hi,

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

The lldb CMake files use this, and I think I'm seeing build failures
on Linux because it no longer provides "-fno-rtti" to the compiler.
Unfortunately I couldn't spot an obvious replacement from the commit
("LLVM_NO_RTTI 1" -> "LLVM_REQUIRES_RTTI OFF" seemed to have no
effect).

Can you suggest anything helpful?

Cheers.

Tim.