After PR #138514, only 3 testsuite failures remain on Solaris/amd64. One
of them is
```
libomp :: ompt/loadtool/tool_available_search/tool_available_search.c
```
The issue is that the expected message is that emitted by Linux/glibc,
while the Solaris message differs:
On Linux/x86_64, I get
```
Opening projects/openmp/runtime/test/ompt/loadtool/tool_available_search/Output/non_existing_file.so... Failed: projects/openmp/runtime/test/ompt/loadtool/tool_available_search/Output/non_existing_file.so: cannot open shared object file: No such file or directory
```
while Solaris/amd64 emits
```
Opening projects/openmp/runtime/test/ompt/loadtool/tool_available_search/Output/non_existing_file.so... Failed: ld.so.1: tool_available_search.c.tmp: projects/openmp/runtime/test/ompt/loadtool/tool_available_search/Output/non_existing_file.so: open failed: No such file or directory
```
Since the exact wording is obviously an implementation detail, this
patch allows for both forms.
Tested on `amd64-pc-solaris2.11` and `x86_64-pc-linux-gnu`.
fe56c8f364