Currently, only x86/arm/aarch64 support .plt probes. However, the process_by_pid.exp testcase always tries to use .plt probes, causing failures on all other arches.

The testcase does the equivalent of the following (this is from a ppc64 system):

====
# stap -p4 ../src/testsuite/systemtap.base/process_by_pid.stp 123
semantic error: while resolving probe point: identifier 'process' at ../src/testsuite/systemtap.base/process_by_pid.stp:12:7
        source: probe process($1).function("*") {
                      ^

semantic error: no match

Pass 2: analysis failed.  [man error::pass2]
Number of similar error messages suppressed: 4.
Rerun with -v to see them.
====