Revert "[compile][startup] Disable C++ compilation of symbolic shapes"

[xiszishu]

Reverts #20836

due to the issue in #20836 (comment)
and #20836 (comment)

[github-actions]

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[gemini-code-assist]

Code Review

This pull request reverts a previous change that disabled C++ compilation of symbolic shapes. The original change, intended to improve compile time, unfortunately introduced a critical bug causing compilation failures for models with dynamic shapes. This revert correctly removes the problematic code, restoring the previous stable behavior. The change is clean and necessary. I see no issues with this revert.