* Add missing includes.
* Add parenthesis around operators to suppress compiler warning.
* Remove duplicate definition of is_supported_aux_t.
* Explicitly create descriptions.
* Remove usage of anonymous struct with non-trivially constructible members.
This is an error on some compilers (e.g. gcc).
* Remove unnecessary rvalue-reference on pointer type.
* Explicitly construct SamplerParams to suppress compiler warnings.
* Place attribute specifier before declaration.
* Remove usage of anonymous struct with a non-trivially constructible member.
Replace the `array` union member with an `operator[]` to provide similar
functionality.
Some compilers (e.g. gcc) do not support this non-standard use-case.
* Use same warning settings as main filament project.