Fix wasm compile error with lseek64, ftruncate64

BeefySysLib/platform/wasm/WasmCommon.cpp

@@ -1,3 +1,6 @@
+#define lseek64 lseek
+#define ftruncate64 ftruncate
+
 #include "../posix/PosixCommon.cpp"
 
 extern "C" uintptr_t _Unwind_GetIP(struct _Unwind_Context *context)