For PR797:

For PR797:
Make sys::Program::ExecuteAndWait not throw exceptions and update any
affected code. It now return -9999 to signal that the program couldn't be
executed. Only one case (in bugpoint) actually examines the result code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29785 91177308-0d34-0410-b5e6-96231b3b80d8