when passing an int to a string enum. Previously, the int was coerced to
a string. The JIT skips parameter clean up when unnecessary. In this
particular case, passing int to from(int|string) normally doesn't cause
a coercion so no dtor for the $value zval is generated.
To circumvent this we avoid coersion by explicitly allowing ints and
converting them to strings ourselves. Then we can free it appropriately.
See GH-8518
Closes GH-8633
Instead mark name/value as readonly and the class as
NO_DYNAMIC_PROPERTIES. This gives us the desired limitations
using native features.
In fact, this also fixes a bug where opcache cache slot merging
might result in a write to the name/value properties being
allowed. The readonly implementation handles this case correctly.
This adds support for internal enums with the same basic approach
as userland enums. Enum values are stored as CONSTANT_AST and
objects created during constant updating at runtime. This means
that we need to use mutable_data for internal enums.
This just adds basic support and APIs, it does not include the
stubs integration from #7212.
Closes GH-7302.
