[interp] Forcibly enable intrinsics when we encounter a must-expand call

[kg]

Right now when testing individual methods from the startup path with the interpreter a lot of them fail due to stack overflow. This is because we're compiling a must expand intrinsic with the interpreter, which will recurse infinitely.

• When encountering a must expand intrinsic self-call in an interpreted method, always expand it even if intrinsics are turned off.
• Clean up a minor edge case in the 'is reference or contains references' intrinsic
• Remove an alignment assert that is causing failures in the startup path

[kg]

The failures on CI don't reproduce locally, it seems like when I run locally the test suite just exits early and is recorded as passing. Looking into it.

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