make leaner bindings

[gdamjan]

iterate over the php include directories, and update the builder to only create bindings from the header files in those directories. This omits all of the other non-php related types and functions from the bindings, and avoids the need to explicitly add hundreds of functions to the blocklist.

With that php_bindings.rs also become 14000 lines smaller
48803 php_bindings.rs.old
34222 php_bindings.rs

also fixed compile errors related to the _Float64x type no functions using it are in the bindings any more

[gdamjan]

just an example of the compile failures before this patch

❯ cargo build
   Compiling phper-sys v0.5.1 (/home/damjan/src/phper/phper-sys)
error[E0412]: cannot find type `_Float64x` in this scope
     --> /home/damjan/src/phper/target/debug/build/phper-sys-caf06ff3c34bff86/out/php_bindings.rs:10412:30
      |
3040  | pub type _Float64 = f64;
      | ------------------------ similarly named type alias `_Float64` defined here
...
10412 |     pub fn fminimumf64x(__x: _Float64x, __y: _Float64x) -> _Float64x;
      |                              ^^^^^^^^^ help: a type alias with a similar name exists: `_Float64`

error[E0412]: cannot find type `_Float64x` in this scope
     --> /home/damjan/src/phper/target/debug/build/phper-sys-caf06ff3c34bff86/out/php_bindings.rs:10412:46
      |
3040  | pub type _Float64 = f64;
      | ------------------------ similarly named type alias `_Float64` defined here
...
10412 |     pub fn fminimumf64x(__x: _Float64x, __y: _Float64x) -> _Float64x;
      |                                              ^^^^^^^^^ help: a type alias with a similar name exists: `_Float64`

[jmjoy]

I think you should pass the CI and then I can review it.

[jmjoy]

Thanks for your excellent work!