[clang] [libclang/python] Fix bug in `SourceRange.__contains__`, add tests (PR #101802)

[Aaron Ballman via cfe-commits]

================
@@ -50,6 +50,17 @@ unsigned clang_equalLocations(CXSourceLocation loc1, CXSourceLocation loc2) {
           loc1.int_data == loc2.int_data);
 }
 
+unsigned clang_lessThanLocations(CXSourceLocation loc1, CXSourceLocation loc2) {
+  const SourceLocation Loc1 = SourceLocation::getFromRawEncoding(loc1.int_data);
+  const SourceLocation Loc2 = SourceLocation::getFromRawEncoding(loc2.int_data);
+
+  const SourceManager &SM =
+      *static_cast<const SourceManager *>(loc1.ptr_data[0]);
+  // Use the appropriate SourceManager method here rather than operator< because
+  // ordering is meaningful only if LHS and RHS have the same FileID
----------------
AaronBallman wrote:

```suggestion
  // ordering is meaningful only if LHS and RHS have the same FileID.
```

https://github.com/llvm/llvm-project/pull/101802