[OpenMP][test] Make %p 0x prefix optional (#138514)
Testing `openmp` on Solaris/amd64 shows a large number of failures, all
due to the same issue:
```
# .---command stderr------------
# | openmp/runtime/test/ompt/misc/interoperability.cpp:67:16: error: CHECK-SAME: expected string not found in input
# | // CHECK-SAME: parent_task_frame.reenter={{0x[0-f]+}}
# | ^
# | <stdin>:5:101: note: scanning from here
# | 281474976710658: ompt_event_parallel_begin: parent_task_id=281474976710659, parent_task_frame.exit=0, parent_task_frame.reenter=7fffbedffe90, parallel_id=281474976710661, requested_team_size=2, codeptr_ra=408b8e, invoker=2
```
The testsuite expects pointers to be printed with a `0x` prefix when
using the `%p` format, while Solaris `libc` just prints them in hex
without a prefix.
However, this difference is completely benign. ISO C (up to C23,
7.23.6.1) states
```
p The argument shall be a pointer to void or a pointer to a character
type. The value of the pointer is converted to a sequence of printing
characters, in an implementation-defined manner.
```
I saw two ways around this:
- replace every instance of `%p` with a macro (`KMP_PTR_FMT`, defined as
`"%p"` or `"0x%p" as appropriate), or
- adjust the testsuite to make the `0x` prefix optional
The second route seemed less intrusive and more readable, so that's what
this patch does. While large, it's also completely mechanical.
Tested on `amd64-pc-solaris2.11` and `x86_64-pc-linux-gnu`.
