scratch - suppress build of llvm_c_test

llvm_c_test requires a path to llvm that is not published.  The patch
is a simple function to obtain a pointer to the generated function so
that the invocation of a generated function can be done directly via
the function pointer rather than asking an LLVM API function to perform
the invocation.
Currently RegEx generates C code and uses clang rather than generating
LLVM bitcode.  The LLVM patch needs to be either publshed or even
forwarded to LLVM when clang gets removed from R-Framework.