[drewmt]

Fixes phpstan/phpstan#15380.

When PHPStan runs on a PHP version without native enum reflection, BetterReflection uses its generic class adapter. The enum-specific class check then misses RoundingMode::HalfAwayFromZero, and resolving the default for round() asks a unit enum case for a backing value, causing the reported LogicException.

Check whether the reflected constant is an enum case before reading its value expression, returning the existing EnumCaseObjectType instead.

The regression parses a unit enum directly and uses the real generic class adapter, avoiding the runtime's RoundingMode polyfill on older PHP versions. It fails with the reported exception before the fix and passes afterward.

AnalyserIntegrationTest::testBug15380 also analyses the reported round(1.5) call with phpVersion: 80500, using a separate test container and restoring the original container afterward. The fixture consumes the result so the unrelated no-effect rule does not obscure crash coverage.

For a red/green check on the development runtime, I temporarily selected the generic class adapter used by old PHP runtimes and removed the existing enum-case guard. The integration test threw the reported LogicException; restoring the guard made it pass. Both temporary production edits were then reverted. This simulation is not an actual PHP 7.4 run.

Validation on PHP 8.4.12:

• Full configured ParaTest suite: 21,713 tests, 96,935 assertions, 106 skips, no failures or errors.
• Analyser integration suite: 202 tests, 668 assertions, no failures or errors.
• Focused resolver suite: 8 tests, 16 assertions.
• Scoped PHPStan analysis and project coding standards pass for the changed integration test.

The full configured suite also passes on PHP 8.3.33: 21,567 tests, 96,687 assertions, 204 skips, no failures or errors. Its analyser integration suite has 202 tests, 667 assertions and one existing skip. The focused resolver suite passes on both runtimes.

I have not run the packaged PHAR on PHP 7.4 locally; the regression deliberately exercises its generic-adapter path on the development runtime.

[drewmt]

Updated the regression fixture to avoid the runtime RoundingMode polyfill on older PHP versions. It now parses a unit enum directly; the full local suites pass on PHP 8.3 and 8.4.

[drewmt]

I checked the current-head failures. The pinned Larastan suite has the same two failures with the upstream base PHAR and this PR’s PHAR; Doctrine also reports the same 28 errors with both builds. The PHP 8.6 extension jobs fail during Composer dependency resolution, and Analyse (7) fails uploading its artifact (ENOTFOUND). The other integration errors also appear in the independent #6679 run. I have left the focused fix unchanged.