`try` is a keyword in C++, and as such C++ code including <zend_enum.h>
fails to compile unless a workaround is in place. To resolve this, we
simply rename the parameter.
We choose `try_from` to make it clear that this parameter is true when
the function is called from `BackedEnum::tryFrom()`. For consistency,
we also rename the `try` parameter of `zend_enum_from_base()`, although
that function is not exported.
This issue had been reported by @oplanre, who also provided an initial
PR.
Closes GH-15259.
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.
