[lldb][test] Add test for parsing Objective-C synthesized properties

Prior to llvm#164998, recent LLDB
versions would fail to parse synthesized property setters correctly. The
only way this failure would manifest is an error to the console:
```
error: main.o [0x00000000000000cd]: invalid Objective-C method DW_TAG_subprogram (DW_TAG_subprogram), please file a bug and attach the file at the start of this error message
```

There weren't any Objective-C tests that failed when the original regression (llvm#100355) landed. This patch adds a test that explicitly checks that the type of the setter is sensible.

This test fails without llvm#164998
and passes with it.

I decided not to check for the absence of the console error because that kind of test would be fragile to the removal of (or any changes to) the error message.

Author: Michael137

lldb/test/API/lang/objc/synthesized-property-accessor/Makefile

@@ -0,0 +1,4 @@
+OBJC_SOURCES := main.m
+LDFLAGS := -lobjc
+
+include Makefile.rules

lldb/test/API/lang/objc/synthesized-property-accessor/TestSynthesizedPropertyAccessor.py

@@ -0,0 +1,30 @@
+"""
+Test debug-info parsing of synthesized Objective-C properties.
+"""
+
+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class TestSynthesizedPropertyAccessor(TestBase):
+    def test(self):
+        self.build()
+
+        (target, _, _, _) = lldbutil.run_to_source_breakpoint(
+            self, "return f.fooProp", lldb.SBFileSpec("main.m")
+        )
+
+        getters = target.FindFunctions("-[Foo fooProp]", lldb.eFunctionNameTypeSelector)
+        self.assertEqual(len(getters), 1)
+        getter = getters[0].function.GetType()
+        self.assertTrue(getter)
+        self.assertEqual(getter.GetDisplayTypeName(), "int ()")
+
+        setters = target.FindFunctions(
+            "-[Foo setFooProp:]", lldb.eFunctionNameTypeSelector
+        )
+        self.assertEqual(len(setters), 1)
+        setter = setters[0].function.GetType()
+        self.assertTrue(setter)
+        self.assertEqual(setter.GetDisplayTypeName(), "void (int)")

lldb/test/API/lang/objc/synthesized-property-accessor/main.m

@@ -0,0 +1,14 @@
+#import <Foundation/Foundation.h>
+
+@interface Foo : NSObject
+@property(readwrite) int fooProp;
+@end
+
+@implementation Foo
+@end
+
+int main() {
+  Foo *f = [Foo new];
+  [f setFooProp:10];
+  return f.fooProp;
+}