[ORC] skip reoptimization tests on ARM

It failed on armv7 with "Architecture not supported" which is due to
StubTests being not supported on ARM

	/builds/fossdd/aports/main/llvm20/src/llvm-project-20.1.0.src/llvm/unittests/ExecutionEngine/Orc/ReOptimizeLayerTest.cpp:140: Failure
	Value of: llvm::detail::TakeError(RM.takeError())
	Expected: succeeded
	  Actual: failed  (Architecture not supported) (of type llvm::detail::ErrorHolder)

Author: fossdd

llvm/unittests/ExecutionEngine/Orc/ReOptimizeLayerTest.cpp

@@ -55,6 +55,10 @@ class ReOptimizeLayerTest : public testing::Test {
     if (Triple.isPPC())
       GTEST_SKIP();
 
+    // ARM is not supported yet.
+    if (Triple.isARM())
+      GTEST_SKIP();
+
     auto EPC = SelfExecutorProcessControl::Create();
     if (!EPC) {
       consumeError(EPC.takeError());