Request: Add a LLVM_VERSION define to llvm-c/core.h or llvm/Config/config.h

Hi,

Would it be possible to add a define of the LLVM version in the headers?

Something like

  #define LLVM_VERSION 0x0207

or

  #define LLVM_VERSION_MAJOR 2
  #define LLVM_VERSION_MINOR 7

This would simplify supporting more than one LLVM version (typically
latest stable and head) from external projects.

We are using some complicated logic to achieve the above with from
"llvm-config --version", but an official way to know the version would
be nice.

Jose