1. move gnu compile flags "-pipe -Wshadow" from root "CMakeLists.txt" to "cmake/define.inc"; and change compile flag "/O3" to "/O2", because "/O3" is not supported by MSVC.
2. fix compile warnings in "src/util/src/tbuffer.c", by using "union" to transform integer with float and double.
3. use "memcpy()" instead of directly type convert in "rc/util/src/tutil.c" to resolve memory alignment problem in ARM platform.
4. reduce other compile warnings.