Allow using mmap for shared memory if hw bound check is disabled (#3029)

For shared memory, the max memory size must be defined in advanced. Re-allocation
for growing memory can't be used as it might change the base address, therefore when
OS_ENABLE_HW_BOUND_CHECK is enabled the memory is mmaped, and if the flag is
disabled, the memory is allocated. This change introduces a flag that allows users to use
mmap for reserving memory address space even if the OS_ENABLE_HW_BOUND_CHECK
is disabled.

core/shared/platform/android/platform_internal.h

@@ -80,8 +80,6 @@ typedef jmp_buf korp_jmpbuf;
 #define os_longjmp longjmp
 #define os_alloca alloca
 
-#define os_getpagesize getpagesize
-
 typedef void (*os_signal_handler)(void *sig_addr);
 
 int
@@ -101,6 +99,8 @@ os_sigreturn();
 #endif /* end of BUILD_TARGET_X86_64/AMD_64/AARCH64/RISCV64 */
 #endif /* end of WASM_DISABLE_HW_BOUND_CHECK */
 
+#define os_getpagesize getpagesize
+
 typedef long int __syscall_slong_t;
 
 #if __ANDROID_API__ < 19