This adds a script called build.py as well as a lit substitution
called %build that we can use to invoke it. The idea is that
this allows a lit test to build test inferiors without having
to worry about architecture / platform specific differences,
command line syntax, finding / configurationg a proper toolchain,
and other issues. They can simply write something like:
%build --arch=32 -o %t.exe %p/Inputs/foo.cpp
and it will just work. This paves the way for being able to
run lit tests with multiple configurations, platforms, and
compilers with a single test.
Differential Revision: https://reviews.llvm.org/D54914
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@348058 91177308-0d34-0410-b5e6-96231b3b80d8
Zachary Turner
c3ceb23729