Toolchain: Remove workarounds for initializer_list and _aligned_alloc

These are no longer required to use libc++ on Serenity

Toolchain/Patches/llvm/0005-libc-Add-support-for-SerenityOS.patch

@@ -10,24 +10,17 @@ LibC, namely:
 * The number of errno constants defined by us is given by the value of
  the `ELAST` macro.
 * Multithreading is implemented though the pthread library.
-* Aligned memory allocation is provided by the MSVCRT-like
- `_aligned_{malloc,free}` functions.
-
-Adds a hack for a header not found error when including
-`<initializer_list>` inside the SerenityOS kernel.
-
-Makes libc++ use its builtin character type table instead of the one
-provided by LibC as it is incomplete.
+* Use libc++'s builtin character type table instead of the one provided
+ by LibC as there's a lot of extra porting work to convince the rest of
+ locale.cpp to use our character type table properly.
 ---
  libcxx/include/CMakeLists.txt | 1 +
  libcxx/include/__config | 6 ++++--
  libcxx/include/__locale | 2 ++
  libcxx/include/__support/serenity/xlocale.h | 24 +++++++++++++++++++++
- libcxx/include/initializer_list | 2 ++
  libcxx/include/locale | 2 +-
- libcxx/include/new | 4 ++--
  libcxx/src/include/config_elast.h | 2 ++
- 8 files changed, 38 insertions(+), 5 deletions(-)
+ 6 files changed, 34 insertions(+), 3 deletions(-)
  create mode 100644 libcxx/include/__support/serenity/xlocale.h
 
 diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
@@ -109,20 +102,6 @@ index 000000000..0f939d2f6
 +#endif // __serenity__
 +
 +#endif
-diff --git a/libcxx/include/initializer_list b/libcxx/include/initializer_list
-index fefaf8cf8..c388bc246 100644
---- a/libcxx/include/initializer_list
-+++ b/libcxx/include/initializer_list
-@@ -43,7 +43,9 @@ template<class E> const E* end(initializer_list<E> il) noexcept; // constexpr in
- */
-
- #include <__config>
-+#if !defined(__serenity__) || !defined(KERNEL)
- #include <cstddef>
-+#endif
-
- #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
- #pragma GCC system_header
 diff --git a/libcxx/include/locale b/libcxx/include/locale
 index 7c2d2361f..229ca7258 100644
 --- a/libcxx/include/locale
@@ -136,28 +115,6 @@ index 7c2d2361f..229ca7258 100644
  # define _LIBCPP_HAS_CATOPEN 1
  # include <nl_types.h>
  # endif
-diff --git a/libcxx/include/new b/libcxx/include/new
-index be0d972f4..d212bae46 100644
---- a/libcxx/include/new
-+++ b/libcxx/include/new
-@@ -320,7 +320,7 @@ inline _LIBCPP_INLINE_VISIBILITY void __libcpp_deallocate_unsized(void* __ptr, s
- // Returns the allocated memory, or `nullptr` on failure.
- inline _LIBCPP_INLINE_VISIBILITY
- void* __libcpp_aligned_alloc(std::size_t __alignment, std::size_t __size) {
--#if defined(_LIBCPP_MSVCRT_LIKE)
-+#if defined(_LIBCPP_MSVCRT_LIKE) || (defined(__serenity__) && !defined(KERNEL))
- return ::_aligned_malloc(__size, __alignment);
- #else
- void* __result = nullptr;
-@@ -332,7 +332,7 @@ void* __libcpp_aligned_alloc(std::size_t __alignment, std::size_t __size) {
-
- inline _LIBCPP_INLINE_VISIBILITY
- void __libcpp_aligned_free(void* __ptr) {
--#if defined(_LIBCPP_MSVCRT_LIKE)
-+#if defined(_LIBCPP_MSVCRT_LIKE) || (defined(__serenity__) && !defined(KERNEL))
- ::_aligned_free(__ptr);
- #else
- ::free(__ptr);
 diff --git a/libcxx/src/include/config_elast.h b/libcxx/src/include/config_elast.h
 index 0ed53a3b2..7fffd937e 100644
 --- a/libcxx/src/include/config_elast.h