Revert "[Driver] Quote clang full version in dwarf producer when invoking cc1as"

This reverts commit r264813 / 6484b95d634f53dd929c75265ef3c4decf397584.

While using it in the shell is fine, this a problem when cc1as is
invoked directly by the driver because single quoting the clang full
version makes cc1as write out the version with the quotes in the final
binary.

If the user wants to copy-n-pastable output, it could use either -###
or CC_PRINT_OPTIONS=1 clang -v ...

llvm-svn: 268297