Revert "Attempt to disable MLIR JIT tests on PowerPC to unbreak the bot"

This reverts commit 652f4b5140.

Re-enable MLLIR JIT tests.
The MLIR Bot was updated to export LD_LIBRARY_PATH=/usr/lib64, which
seem to fix this issue.

mlir/test/Unit/lit.cfg.py

@@ -37,7 +37,3 @@ if 'HOME' in os.environ:
 for symbolizer in ['ASAN_SYMBOLIZER_PATH', 'MSAN_SYMBOLIZER_PATH']:
     if symbolizer in os.environ:
         config.environment[symbolizer] = os.environ[symbolizer]
-
-# FIXME: PPC needs to be switched to use the large code model
-if 'powerpc' in config.host_triple:
-    config.unsupported = True

mlir/test/Unit/lit.site.cfg.py.in

@@ -11,7 +11,6 @@ config.shlibdir = "@SHLIBDIR@"
 config.mlir_src_root = "@MLIR_SOURCE_DIR@"
 config.mlir_obj_root = "@MLIR_BINARY_DIR@"
 config.mlir_tools_dir = "@MLIR_TOOLS_DIR@"
-config.host_triple = "@LLVM_HOST_TRIPLE@"
 
 # Support substitution of the tools_dir and build_mode with user parameters.
 # This is used when we can't determine the tool dir at configuration time.

mlir/test/mlir-cpu-runner/lit.local.cfg

@@ -4,10 +4,6 @@ import sys
 if sys.platform == 'win32':
     config.unsupported = True
 
-# FIXME: PPC needs to be switched to use the large code model
-if 'powerpc' in config.host_triple:
-    config.unsupported = True
-
 # Requires a non-empty default triple for these tests.
 # Passing ` -DLLVM_DEFAULT_TARGET_TRIPLE="" ` when the
 # host target isn't available is how LLVM filters