Update based on php-src implementation

Allocate error on the stack

Revert context return

On second thought, this wasn’t actually useful.

Remove fcontext_t and transfer_t from fiber.h

We don’t really want to define these outside of fiber_asm.c.

Use preallocated context

Removed just-added data pointer as this approach makes it unnecessary.

Provide fiber context to and from internal API functions

make_fcontext aligns pointer

No need to align the stack pointer manually, make_fcontext already does this.

Free context on error

Few other minor nits

A few minor fixes and nits

Minor stylistic changes

Combine create and initialize context functions

zend_fiber_create_context had been reduced to a malloc function and felt unnecessary.

Remove initialized flag

Remove root context

Remove initial jump/suspend

Update file header

Thanks to Martin Schröder for the original code and inspiration, but I should be the main contact for questions and maintance of this code. Very little of the original cod

Update file header

Thanks to Martin Schröder for the original code and inspiration, but I should be the main contact for questions and maintance of this code. Very little of the original code remains unchanged.

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Remove initialized flag

Remove root context

Remove initial jump/suspend

Update file header

Thanks to Martin Schröder for the original code and inspiration, but I should be the main contact for questions and maintance of this code. Very little of the original cod

Update file header

Thanks to Martin Schröder for the original code and inspiration, but I should be the main contact for questions and maintance of this code. Very little of the original code remains unchanged.

show more ...

Remove indirection for fiber context

Since asm is always used, zend_fiber_context can be defined as a struct instead of a void*.

Update boost

Use combined asm on macOS. Fixes #17.

Fix line-endings

These files had Windows line-endings.

Adjust stack alignment

[boost.context](https://github.com/boostorg/context/blob/1f955ef26de5e48c26217c423592308f57d1c615/include/boost/context/fiber_fcontext.hpp#L164) says the stack should

Adjust stack alignment

[boost.context](https://github.com/boostorg/context/blob/1f955ef26de5e48c26217c423592308f57d1c615/include/boost/context/fiber_fcontext.hpp#L164) says the stack should be 16-byte aligned.

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Clearer context creation

Better descriptions of pointer calculations.