[CORE] Use new for singleton to prevent de-alloc order issues

[tqchen]

This PR updates the logic to use new for singleton to prevent potential de-alloc order issues during program shutdown

[gemini-code-assist]

Summary of Changes

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This pull request refines the memory management strategy for a core singleton instance, TypeTable, by transitioning its allocation from static storage to dynamic heap allocation using the new operator. This modification is crucial for preventing subtle de-allocation order issues that can arise during program termination, particularly when modules are being unloaded, thereby enhancing the overall stability and robustness of the application during shutdown sequences.

Highlights

• Singleton Lifetime Management: The instantiation method for the TypeTable singleton within the Global() static method has been updated to use new for heap allocation.
• De-allocation Order Issues: This change specifically addresses potential de-allocation order problems that can occur during program shutdown, especially in scenarios involving module unloading, by ensuring the singleton instance lives longer.

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[gemini-code-assist]

Code Review

This pull request correctly addresses a potential static de-allocation order issue by changing the TypeTable singleton to be heap-allocated with new and intentionally leaking it. This is a standard and effective pattern to ensure the singleton's lifetime persists until program termination, thus avoiding the static deinitialization order fiasco. The change is well-reasoned and the implementation is correct. I have one minor suggestion to fix a typo in a comment for clarity.