If we just compile with -O0, clang will add optnone attributes
everywhere, so opt won't actually be able to perform any passes.
Instruct clang to not emit the optnone so opt can do its thing.
Differential Revision: https://reviews.llvm.org/D56950
llvm-svn: 352550
------------------------------
If you find that a bug crashes in the optimizer, compile your test-case to a
-``.bc`` file by passing "``-emit-llvm -O0 -c -o foo.bc``".
-Then run:
+``.bc`` file by passing "``-emit-llvm -O1 -Xclang -disable-llvm-passes -c -o
+foo.bc``". Then run:
.. code-block:: bash