[llvm][test] Skip physical filesystem test if unsupported

[benlangmuir]

Summary

We are relying on deleting the working directory to trigger a later error in getcwd, but some platforms (e.g. Solaris) disallow deleting the working directory of the process. Skip the test in that case.

[ro]

Both Solaris buildbots are one failure down again. Thanks for the quick fix.

llvm/unittests/Support/VirtualFileSystemTest.cpp

TEST(VirtualFileSystemTest, PhysicalFileSystemWorkingDirFailure) {
   SmallString<128> WD, PrevWD;
   ASSERT_EQ(sys::fs::current_path(PrevWD), std::error_code());
   ASSERT_EQ(sys::fs::createUniqueDirectory("d1", WD), std::error_code());
   ASSERT_EQ(sys::fs::set_current_path(WD), std::error_code());
   auto Restore =
       llvm::make_scope_exit([&] { sys::fs::set_current_path(PrevWD); });
 
   // Delete the working directory to create an error.
-  ASSERT_EQ(sys::fs::remove_directories(WD), std::error_code());
+  if (sys::fs::remove_directories(WD, /*IgnoreErrors=*/false))
+    // Some platforms (e.g. Solaris) disallow removal of the working directory.
+    GTEST_SKIP() << "test requires deletion of working directory";
 
   // Verify that we still get two separate working directories.
   auto FS1 = vfs::createPhysicalFileSystem();
   auto FS2 = vfs::createPhysicalFileSystem();
   ASSERT_EQ(FS1->getCurrentWorkingDirectory().getError(),
             errc::no_such_file_or_directory);
   ASSERT_EQ(FS1->setCurrentWorkingDirectory(D2.path()), std::error_code());
   ASSERT_EQ(FS1->getCurrentWorkingDirectory().get(), D2.path());