Now that all supported build systems create a valid dotest.py
invocation, we no longer need to guess the directory where any of the
llvm tools live. Additionally, the current logic is incomplete: it
doesn't try to find any other tools than FileCheck, such as dsymutil for
example.
If no FileCheck is provided, we should print a warning and skip the
tests that need it, but that's not part of this patch.
Differential revision: https://reviews.llvm.org/D66893
llvm-svn: 370232