compile with -fno-omit-frame-pointer

compile with -fno-omit-frame-pointer

By default, depending on the version, gcc can reuse the frame pointer register.
This is a micro-optimization that might help on some very old x86 processors.
However, it also makes dynamic tracing less useful because the stacks cannot
be easily observed.

This rule change instructs gcc to use the -fno-omit-frame-pointer option
when compiling.

Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Elling <Richard.Elling@RichardElling.com>
Closes #8617