llvm-exegesis: Only run X86 tests on X86 hosts

[tstellar]

Summary

These tests were failing on SystemZ host, I don't think JIT'ing X86
modules on SystemZ is supported.

The tests were initiallay enabled on all arches by
7a76140220bd2c4730a2c39b6fd645402040f011.

[tstellar]

Fix PowerPC tests too.

[courbet]

I don't think JIT'ing X86 modules on SystemZ is supported.

This is weird, right ? the JITing code should be purely target agnostic. Do you have a link to a failing test so I can have a look ?

In the meantime I'm fine submitting this, the main use case is to JIT and run on the same architecture.

[tstellar]

From what I can tell the problem is not the JIT'd code, but registering the EHFrames. Maybe the endian differences make libgcc not able to read the EHFrames since they are generated for x86. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108994#c14

[gchatelet]

Thx for the heads up / fix @tstellar !

llvm/test/tools/llvm-exegesis/PowerPC/lit.local.cfg

 if not ('PowerPC' in config.root.targets):
     # We need support for PowerPC.
     config.unsupported = True
+elif not ('powerpc' in config.root.host_triple):
+    # We need to be running on an PPC host.
+    config.unsupported = True

llvm/test/tools/llvm-exegesis/X86/lit.local.cfg

 if not ('X86' in config.root.targets):
     # We need support for X86.
     config.unsupported = True
+elif not ('x86_64' in config.root.host_triple):
+    # We need to be running on an X86 host.
+    config.unsupported = True