[lldb] Ignore linkage diagnostic for LLDBSwigPythonBreakpointCallbackFunction (NFC)

Ignore `-Wreturn-type-c-linkage` diagnostics for `LLDBSwigPythonBreakpointCallbackFunction`.

The function is defined in `python-wrapper.swig` which uses `extern "C" { ... }` blocks.
The declaration of this function in `ScriptInterpreterPython.cpp` already uses these
same pragmas to silence the warning there.

This prevents `-Werror` builds from failing.

Differential Revision: https://reviews.llvm.org/D98368

Author: kastiglione

lldb/bindings/python/python-wrapper.swig

@@ -39,6 +39,17 @@ private:
 // This function is called by lldb_private::ScriptInterpreterPython::BreakpointCallbackFunction(...)
 // and is used when a script command is attached to a breakpoint for execution.
 
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wreturn-type-c-linkage"
+
+// Disable warning C4190: 'LLDBSwigPythonBreakpointCallbackFunction' has
+// C-linkage specified, but returns UDT 'llvm::Expected<bool>' which is
+// incompatible with C
+#if _MSC_VER
+#pragma warning (push)
+#pragma warning (disable : 4190)
+#endif
+
 SWIGEXPORT llvm::Expected<bool>
 LLDBSwigPythonBreakpointCallbackFunction
 (
@@ -85,6 +96,12 @@ LLDBSwigPythonBreakpointCallbackFunction
     return result.get().get() != Py_False;
 }
 
+#if _MSC_VER
+#pragma warning (pop)
+#endif
+
+#pragma clang diagnostic pop
+
 // This function is called by lldb_private::ScriptInterpreterPython::WatchpointCallbackFunction(...)
 // and is used when a script command is attached to a watchpoint for execution.