Workaround Clang hangs indefinitely

When building the function under -O1, Clang hangs indefinitely. It works
fine under either -O0 or -O2. Workaround by turning off optimization for
just the offending function.

Test: presubmit
Bug: 296850773
Bug: 294796809
Change-Id: Ia72a9e9e56183d71296cd5d8628461197cb5b2a4