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Chris Tateandblurname
d1f3eda732
Object.freeze of an array that another reference may still hold stopped at compile time with SC2020, and freezing an array, Map or Set held in an untyped value threw SC2020 at run time. Node freezes the object itself: a frozen array refuses every later write through any reference with the TypeError of the operation's first write, and a frozen Map or Set only stops being extensible, since its entries are not properties. - An array a program may freeze keeps a frozen bit in its storage flags. An array type is freezable when a typed Object.freeze names it, or, in a program that freezes untyped values, when a value of it can be held as a live untyped reference. The writes of those types test the bit with the guard published arrays already use; other array types are unchanged. - The guard's errors follow Node for every operation: splice, fill, copyWithin, sort and reverse throw at their first write, and do not throw when they would write nothing. Published arrays get the same errors, and a statement splice of a published array is now guarded. - A Map or Set records that it is not extensible, for Object.freeze, seal and preventExtensions, typed or untyped. Object.isFrozen, isSealed and isExtensible report it, and its entries stay writable. - Writes to a frozen array through an untyped value are refused with the same errors, as are writes to frozen checked arrays and objects, which now name the property and the object as Node does. - Programs that neither freeze nor publish arrays compile to the same IR and LLVM. Corpus 7406 covers typed and untyped freezes of arrays, Maps and Sets, every array write on frozen arrays of zero, one and three elements, comparator sorts, nested arrays, and frozen arrays that are released, and matches Node. Refs #1374 Co-authored-by: blurname <50226652+blurname@users.noreply.github.com>