[lldb][test] TestExprDefinitionInDylib.py adjust test to account for older compiler versions

Skip tests that require `-gstructor-decl-linkage-names` on Clang versions that don't support it.

 Don't pass `-gno-structor-decl-linkage-names` on Clang versions where it the flag didn't exist but it was the default behaviour of the compiler anyway.

Drive-by:
- We used to run `self.expect("Bar()")` which would always fail. So the `error=True` would be true even if we didn't pass the `-gno-structor-linkage-names`. So it wasn't testing the behaviour properly. This patch changes these to `self.expect("expr Bar()")`.

lldb/test/API/lang/cpp/expr-definition-in-dylib/TestExprDefinitionInDylib.py

@@ -6,6 +6,11 @@ from lldbsuite.test import lldbutil
 
 class ExprDefinitionInDylibTestCase(TestBase):
 
+    @skipIf(
+        compiler="clang",
+        compiler_version=["<", "22"],
+        bugnumber="Required Clang flag not supported",
+    )
     @skipIfWindows
     def test_with_structor_linkage_names(self):
         """
@@ -74,7 +79,16 @@ class ExprDefinitionInDylibTestCase(TestBase):
         Tests that if structor declarations don't have linkage names, we can't
         call ABI-tagged constructors. But non-tagged ones are fine.
         """
-        self.build(dictionary={"CXXFLAGS_EXTRAS": "-gno-structor-decl-linkage-names"})
+        # In older versions of Clang the -gno-structor-decl-linkage-names
+        # behaviour was the default.
+        if self.expectedCompiler(["clang"]) and self.expectedCompilerVersion(
+            [">=", "22.0"]
+        ):
+            self.build(
+                dictionary={"CXXFLAGS_EXTRAS": "-gno-structor-decl-linkage-names"}
+            )
+        else:
+            self.build()
 
         target = self.dbg.CreateTarget(self.getBuildArtifact("a.out"))
         self.assertTrue(target, VALID_TARGET)
@@ -95,6 +109,6 @@ class ExprDefinitionInDylibTestCase(TestBase):
 
         self.expect_expr("Foo(10)", result_type="Foo")
 
-        self.expect("Base()", error=True)
+        self.expect("expr Base()", error=True)
 
-        self.expect("Bar()", error=True)
+        self.expect("expr Bar()", error=True)