swift

6af38f3c - [libSyntax] Make RawSyntax nodes hold a strong reference to their arena

[libSyntax] Make RawSyntax nodes hold a strong reference to their arena This allows an elegant design in which we can still allocate RawSyntax nodes using a bump allocator but are able to automatically free that buffer once the last RawSyntax node within that buffer is freed. This also resolves a memory leak of RawSyntax nodes that was caused by ParserUnit not freeing its underlying ASTContext.