This patch adds support for 128-bit floating points in FloatExtractor.
This is required to build SerenityOS on MacOS/aarch64. It might break
building for Raspberry Pi.
Doesn't use them in libc headers so that those don't have to pull in
AK/Platform.h.
AK_COMPILER_GCC is set _only_ for gcc, not for clang too. (__GNUC__ is
defined in clang builds as well.) Using AK_COMPILER_GCC simplifies
things some.
AK_COMPILER_CLANG isn't as much of a win, other than that it's
consistent with AK_COMPILER_GCC.
The commit that introduced BuiltinWrappers (548529a) accidentally used
`val` instead of `value` in the non `__GNUC__` and `__clang__` versions
of the functions.
In order to reduce our reliance on __builtin_{ffs, clz, ctz, popcount},
this commit removes all calls to these functions and replaces them with
the equivalent functions in AK/BuiltinWrappers.h.
The goal of this file is to enable C++ overloaded functions for
standard builtin functions that we use. It contains fallback
implementations for systems that do not have the builtins available.
