Fix a NULL delete via reference bug in LLVM Change-Id: Ie189a528f6f92b7b8b9023d6dcc829130f2f14ec Reviewed-on: https://swiftshader-review.googlesource.com/3161 Reviewed-by: Nicolas Capens <capn@google.com> Tested-by: Greg Hartman <ghartman@google.com>