Fix build

src/mono/mono/utils/dlmalloc.c

@@ -26,9 +26,11 @@
 #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 */