wasi-sdk-pthread.cmake: target rename to wasm32-wasi-threads

after WebAssembly/wasi-libc#381

Author: yamt

wasi-sdk-pthread.cmake

@@ -6,7 +6,7 @@ cmake_minimum_required(VERSION 3.4.0)
 set(CMAKE_SYSTEM_NAME WASI)
 set(CMAKE_SYSTEM_VERSION 1)
 set(CMAKE_SYSTEM_PROCESSOR wasm32)
-set(triple wasm32-wasi-pthread)
+set(triple wasm32-wasi-threads)
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pthread")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pthread")