Add compiler optimizations for release builds

CMakeLists.txt

@@ -24,6 +24,10 @@ else ()
     add_compile_options(-Wall -Wextra -pedantic -Werror)
 endif ()
 
+if (CMAKE_BUILD_TYPE STREQUAL "Release")
+    add_compile_options(-O3 -march=native)
+endif()
+
 add_library(cplchess_lib OBJECT
     Square.cpp
     Move.cpp