Always allocate linear memory using mmap (#3052)

With this approach we can omit using memset() for the newly allocated memory
therefore the physical pages are not being used unless touched by the program.

This also simplifies the implementation.

core/shared/utils/bh_memutils.c

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2024 Amazon Inc.  All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#include "bh_memutils.h"
+
+void *
+bh_memory_remap_slow(void *old_addr, size_t old_size, size_t new_size)
+{
+    void *new_memory =
+        os_mmap(NULL, new_size, MMAP_PROT_WRITE | MMAP_PROT_READ, 0, -1);
+    if (!new_memory) {
+        return NULL;
+    }
+    /*
+     * bh_memcpy_s can't be used as it doesn't support values bigger than
+     * UINT32_MAX
+     */
+    memcpy(new_memory, old_addr, new_size < old_size ? new_size : old_size);
+    os_munmap(old_addr, old_size);
+
+    return new_memory;
+}