Ensure that a WITHOUT ROWID table does not have the .iPKey field set, even if

Ensure that a WITHOUT ROWID table does not have the .iPKey field set, even if
an OOM error occurs while parsing a schema in PRAGMA writable_schema=ON mode.
Add extra assert() statements to triple-check that this never happens.
dbsqlfuzz 803bb1f63d6f3bd6c14db568494d6e96be8f1ec9.

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