[JIT] Allow del statements with multiple targets (#48876)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/48876
**Summary**
This commit adds support for `del` statements with multiple targets.
Targets are deleted left-to-right just like Python.
**Test Plan**
This commit updates the `TestBuiltins.test_del_multiple_operands` unit
test to actually test that multiple deletion works instead of asserting
that an error is thrown.
**Fixes**
This commit fixes #48635.
Test Plan: Imported from OSS
Reviewed By: ZolotukhinM
Differential Revision: D25386285
Pulled By: SplitInfinity
fbshipit-source-id: c0fbd8206cf98b2bd1b695d0b778589d58965a74
