Revert aligned_alloc() addition from MDEV-28836

As pointed out with MDEV-29308 there are issues with the code as is.
MariaDB is built as C++11 / C99. aligned_alloc() is not guarenteed
to be exposed when building with any mode other than C++17 / C11.
The other *BSD's have their stdlib.h header to expose the function
with C+11 anyway, but the issue exists in the C99 code too, the
build just does not use -Werror. Linux globally defines _GNU_SOURCE
hiding the issue as well.

cmake/os/WindowsCache.cmake

@@ -23,7 +23,6 @@ IF(MSVC)
 SET(BFD_H_EXISTS 0 CACHE INTERNAL "")
 SET(HAVE_ACCESS 1 CACHE  INTERNAL "")
 SET(HAVE_ALARM CACHE  INTERNAL "")
-SET(HAVE_ALIGNED_ALLOC CACHE INTERNAL "")
 SET(HAVE_ALLOCA_H CACHE  INTERNAL "")
 SET(HAVE_ARPA_INET_H CACHE  INTERNAL "")
 SET(HAVE_BACKTRACE CACHE  INTERNAL "")

config.h.cmake

@@ -19,7 +19,6 @@
 /* Headers we may want to use. */
 #cmakedefine STDC_HEADERS 1
 #cmakedefine _GNU_SOURCE 1
-#cmakedefine HAVE_ALIGNED_ALLOC 1
 #cmakedefine HAVE_ALLOCA_H 1
 #cmakedefine HAVE_ARPA_INET_H 1
 #cmakedefine HAVE_ASM_TERMBITS_H 1

configure.cmake

@@ -326,14 +326,6 @@ ENDIF()
 CHECK_FUNCTION_EXISTS (accept4 HAVE_ACCEPT4)
 CHECK_FUNCTION_EXISTS (access HAVE_ACCESS)
 CHECK_FUNCTION_EXISTS (alarm HAVE_ALARM)
-IF (CMAKE_SYSTEM_NAME MATCHES "Linux" AND NOT WITH_ASAN)
-  # When an old custom memory allocator library is used, aligned_alloc()
-  # could invoke the built-in allocator in libc, not matching
-  # the overriden free() in the custom memory allocator.
-  SET(HAVE_ALIGNED_ALLOC 0)
-ELSE()
-  CHECK_FUNCTION_EXISTS (aligned_alloc HAVE_ALIGNED_ALLOC)
-ENDIF()
 SET(HAVE_ALLOCA 1)
 CHECK_FUNCTION_EXISTS (backtrace HAVE_BACKTRACE)
 CHECK_FUNCTION_EXISTS (backtrace_symbols HAVE_BACKTRACE_SYMBOLS)

include/aligned.h

@@ -14,8 +14,7 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1335  USA */
 
-#ifdef HAVE_ALIGNED_ALLOC
-#elif defined __linux__
+#if defined __linux__
 # include <malloc.h>
 #endif
 
@@ -23,8 +22,6 @@ inline void *aligned_malloc(size_t size, size_t alignment)
 {
 #ifdef _WIN32
   return _aligned_malloc(size, alignment);
-#elif defined HAVE_ALIGNED_ALLOC
-  return aligned_alloc(alignment, size);
 #elif defined __linux__
   return memalign(alignment, size);
 #else

storage/innobase/buf/buf0flu.cc

@@ -579,9 +579,6 @@ static void buf_tmp_reserve_compression_buf(buf_tmp_buffer_t* slot)
   size= size + LZO1X_1_15_MEM_COMPRESS;
 #elif defined HAVE_SNAPPY
   size= snappy_max_compressed_length(size);
-#endif
-#if defined HAVE_ALIGNED_ALLOC && (defined HAVE_LZO || defined HAVE_SNAPPY)
-  size= MY_ALIGN(size, srv_page_size);
 #endif
   slot->comp_buf= static_cast<byte*>(aligned_malloc(size, srv_page_size));
 }