[llvm-jitlink] Remove flaky testcase. (#175680)
On some systems, backtraces contain addresses with their high bits set*.
These high bits prevent symbolication using the JIT symbol table. Since
this test is for a best-effort debugging / diagnosis tool it seems best
to remove the test until/unless we can get it passing on all systems, or
find some way to identify systems that will fail.
See discussion in https://github.com/llvm/llvm-project/pull/175537.
* Note that the test does not use PAC or pointer tagging -- the high
bits are coming from somewhere else. Possibly libunwind, but that is
just speculation.
