[lldb] Split TestCxxChar8_t

Split TestCxxChar8_t into two parts: one that check reading variables
without a process and another part with. This allows us to skip the
former on Apple Silicon, where lack of support for chained fix-ups
causes the test to fail.

Differential revision: https://reviews.llvm.org/D114819

lldb/test/API/lang/cpp/char8_t/TestCxxChar8_t.py

@@ -15,13 +15,12 @@ class CxxChar8_tTestCase(TestBase):
     mydir = TestBase.compute_mydir(__file__)
 
     @skipIf(compiler="clang", compiler_version=['<', '7.0'])
-    def test(self):
-        """Test that C++ supports char8_t correctly."""
+    @expectedFailureDarwin(archs=["arm64", "arm64e"]) # <rdar://problem/37773624>
+    def test_without_process(self):
+        """Test that C++ supports char8_t without a running process."""
         self.build()
-
         lldbutil.run_to_breakpoint_make_target(self)
 
-        # Make sure the variables can be printed without a running process.
         self.expect("target variable a", substrs=["char8_t", "0x61 u8'a'"])
         self.expect("target variable ab",
                 substrs=["const char8_t *", 'u8"你好"'])
@@ -29,11 +28,16 @@ class CxxChar8_tTestCase(TestBase):
 
         self.expect_expr("a", result_type="char8_t", result_summary="0x61 u8'a'")
         self.expect_expr("ab", result_type="const char8_t *", result_summary='u8"你好"')
+
         # FIXME: This should work too.
         self.expect("expr abc", substrs=['u8"你好"'], matching=False)
 
-        lldbutil.run_break_set_by_source_regexp(self, "// break here", "-f main.cpp")
-        self.runCmd("run")
+
+    @skipIf(compiler="clang", compiler_version=['<', '7.0'])
+    def test_with_process(self):
+        """Test that C++ supports char8_t with a running process."""
+        self.build()
+        lldbutil.run_to_source_breakpoint(self, '// break here', lldb.SBFileSpec("main.cpp"))
 
         # As well as with it
         self.expect_expr("a", result_type="char8_t", result_summary="0x61 u8'a'")