Fix compilation for X32 ABI

/usr/bin/x86_64-pc-linux-gnux32-gcc -DHAVE_CONFIG_H -D_FILE_OFFSET_BITS=64 -Imysql_build/include -Imysql/include -Imysql/mysys  -O2 -pipe -Wall -ggdb -std=gnu17 -fno-strict-aliasing -pie -fPIC -fstack-protector --param=ssp-buffer-size=4 -DNDEBUG -fno-omit-frame-pointer -DDBUG_OFF -Wall -Wdeclaration-after-statement -Wenum-compare -Wenum-conversion -Wextra -Wformat-security -Wmissing-braces -Wno-format-truncation -Wno-init-self -Wno-nonnull-compare -Wno-unused-parameter -Wvla -Wwrite-strings -std=gnu99 -fPIC -MD -MT mysys/CMakeFiles/mysys.dir/my_stack.c.o -MF mysys/CMakeFiles/mysys.dir/my_stack.c.o.d -o mysys/CMakeFiles/mysys.dir/my_stack.c.o -c mysql/mysys/my_stack.c
mysql/include/my_stack_alloc.h: Assembler messages:
mysql/include/my_stack_alloc.h:42: Error: operand type mismatch for `movq'


Fixes commit https://github.com/MariaDB/server/commit/bddbef3573349b0565c43c27beba47c89358f39f
---
--- a/include/my_stack_alloc.h.orig	2025-03-20 12:57:57.478286609 +0100
+++ b/include/my_stack_alloc.h	2025-03-20 12:59:53.789802029 +0100
@@ -38,6 +38,8 @@ static inline void *my_get_stack_pointer
 #if defined(__GNUC__) || defined(__clang__) /* GCC and Clang compilers */
 #if defined(__i386__) /* Intel x86 (32-bit) */
   __asm__ volatile ("movl %%esp, %0" : "=r" (stack_ptr));
+#elif defined(__x86_64__) && defined (__ILP32__) /* Intel x86-64 (64-bit), X32 ABI */
+  __asm__ volatile ("movl %%esp, %0" : "=r" (stack_ptr));
 #elif defined(__x86_64__) /* Intel x86-64 (64-bit) */
   __asm__ volatile ("movq %%rsp, %0" : "=r" (stack_ptr));
 #elif defined(__powerpc__) /* PowerPC (32-bit) */