Revert "Enforce python2 for systems that use python3 as their default."
Revert "Enforce python2 for systems that use python3 as their default."

This reverts commit r200413.

This was breaking the build on systems where the python 2.x executable
was called python.

git-svn-id: e7f1ab7c2a259259587475a3e7520e757882f167@201239 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/libclc,llvm-mirror/libclc,llvm-mirror/libclc,llvm-mirror/libclc,llvm-mirror/libclc,llvm-mirror/libclc,llvm-mirror/libclc