Use sbrk instead of mmap for dlmalloc on wasm

Fix build

src/mono/mono/utils/dlmalloc.c

@@ -19,13 +19,24 @@
  * - the defines below
  */
 
+#include <config.h>
 #include "mono-mmap.h"
 
 #define USE_DL_PREFIX 1
 #define USE_LOCKS 1
+
+#ifdef HOST_WASM
+#pragma clang diagnostic ignored "-Wunused-variable"
+/* Use sbrk to allocate memory, and never release pages since emscripten mmap is fake */
+#define HAVE_MORECORE 1
+#define NO_MALLINFO 1
+#undef HAVE_MMAP
+#define HAVE_MMAP 0
+#else
 /* Use mmap for allocating memory */
 #define HAVE_MORECORE 0
 #define NO_MALLINFO 1
+#endif // HOST_WASM
 #include <mono/utils/dlmalloc.h>
 
 /*