Fix Android build

dlmalloc has been removed and the NDK now exposes a malloc.h header with
malloc_usable_size exposed, so use that.

Also remove the duplication in js__malloc_usable_size.

Fixes: #304

Author: saghul

cutils.h

@@ -38,9 +38,7 @@
 #endif
 #if defined(__APPLE__)
 #include <malloc/malloc.h>
-#elif defined(__ANDROID__)
-#include <dlmalloc.h>
-#elif defined(__linux__) || defined(__CYGWIN__)
+#elif defined(__linux__) || defined(__ANDROID__) || defined(__CYGWIN__)
 #include <malloc.h>
 #elif defined(__FreeBSD__)
 #include <malloc_np.h>
@@ -421,9 +419,7 @@ static inline size_t js__malloc_usable_size(const void *ptr)
     return malloc_size(ptr);
 #elif defined(_WIN32)
     return _msize((void *)ptr);
-#elif defined(__ANDROID__)
-    return dlmalloc_usable_size((void *)ptr);
-#elif defined(__linux__) || defined(__FreeBSD__)
+#elif defined(__linux__) || defined(__ANDROID__) || defined(__CYGWIN__) || defined(__FreeBSD__)
     return malloc_usable_size((void *)ptr);
 #else
     return 0;

quickjs.c

@@ -1734,17 +1734,7 @@ static const JSMallocFunctions def_malloc_funcs = {
     js_def_malloc,
     js_def_free,
     js_def_realloc,
-#if defined(__APPLE__)
-    malloc_size,
-#elif defined(_WIN32)
-    (size_t (*)(const void *))_msize,
-#elif defined(__ANDROID__)
-    (size_t (*)(const void *))dlmalloc_usable_size,
-#elif defined(__linux__) || defined (__CYGWIN__)
-    (size_t (*)(const void *))malloc_usable_size,
-#else
-    NULL,
-#endif
+    js__malloc_usable_size
 };
 
 JSRuntime *JS_NewRuntime(void)