Enable the use of some warnings when building ROCclr
Enable the use of some warnings when building ROCclr

Enabling anything beyond -Wall like -Wextra or -pedantic seems impossible as our code base explodes in thousands of warnings.

-Wno-unused-{variable/function} is not present in the p4 build, but with gcc7.4.0 we get hundreds of instances of this warning being triggered in the code base.

With this change only two warnings show up during the build - -Wsequence-point and -Wunused-but-set-variable. The fix for the first is alredy in review.

Change-Id: I2ff37981377487b0e07fd9490498e38a60792c0c

ROCm-Developer-Tools/ROCclr,ROCm-Developer-Tools/ROCclr