This commit fixes a hang that occurs with debug builds of Open MPI on
aarch64 and power/powerpc systems. When the ll/sc atomics are inline
functions the compiler emits load/store instructions for the function
arguments with -O0. These extra load/store arguments can cause the ll
reservation to be cancelled causing live-lock.
Note that we did attempt to fix this with always_inline but the extra
instructions are stil emitted by the compiler (gcc). There may be
another fix but this has been tested and is working well.
References #3697. Close when applied to v3.0.x and v3.1.x.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>