Enable WASI feature, enhance security and add SGX sample (#142)

Change emcc to clang
Refine interpreter to improve perforamnce

core/iwasm/runtime/include/bh_memory.h

@@ -45,7 +45,7 @@ void bh_memory_destroy();
  * Get the pool size of memory, if memory is initialized with allocator,
  * return 1GB by default.
  */
-int bh_memory_pool_size();
+unsigned bh_memory_pool_size();
 
 #if BEIHAI_ENABLE_MEMORY_PROFILING == 0
 

core/iwasm/runtime/include/wasm_export.h

@@ -110,6 +110,15 @@ wasm_runtime_load_from_sections(wasm_section_list_t section_list,
 void
 wasm_runtime_unload(wasm_module_t module);
 
+#if WASM_ENABLE_WASI != 0
+void
+wasm_runtime_set_wasi_args(wasm_module_t module,
+                           const char *dir_list[], uint32 dir_count,
+                           const char *map_dir_list[], uint32 map_dir_count,
+                           const char *env[], uint32 env_count,
+                           char *argv[], int argc);
+#endif
+
 /**
  * Instantiate a WASM module.
  *