Stdlib: chr() on enum case — VM fatal TYPE_RESOURCE, must TypeError (ext/standard/string.c)

[PurHur]

Summary

Passing a backed enum case to chr() must throw TypeError (Zend 8.2). VM currently hits Undefined constant PHPCompiler\VM\Variable::TYPE_RESOURCE in VmMath::vmTypeName() because TYPE_ENUM_CASE is not handled in parseChrCodepoint() / parseLongBuiltinArgCore().

Umbrella #5524 tracks string builtins generally; this is a hard VM fatal on a common path and should be fixed in VmMath + chr/ord callers.

php-src reference

• ext/standard/string.c — PHP_FUNCTION(chr)

PHP implementation

• ext/standard/VmMath.php — vmTypeName() + early TYPE_ENUM_CASE → TypeError in parseChrCodepoint()
• ext/standard/chr.php (VM + JIT via JitChr)

Repro

php test/repro-maintainer/parity_chr_enum_operand.php
php bin/vm.php test/repro-maintainer/parity_chr_enum_operand.php

Acceptance

• VM emits Zend-parity TypeError: chr(): Argument #1 ($codepoint) must be of type int, E given (enum class name in message).
• Compliance or unit test under test/compliance/cases/stdlib/.

[PurHur]

Merged via #5847 — chr() VM fatal fixed; shared VmMath enum rejection + JitChr lowering. Verification: php bin/vm.php test/repro-maintainer/parity_chr_enum_operand.php