build: bump minimum CMake requirement (#606)

Author: compnerd

CMakeLists.txt

@@ -1,6 +1,4 @@
-cmake_minimum_required(VERSION 3.15.1)
-
-list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules)
+cmake_minimum_required(VERSION 3.19)
 
 project(swift-argument-parser
   LANGUAGES Swift)
@@ -11,15 +9,12 @@ option(BUILD_SHARED_LIBS "Build shared libraries by default" YES)
 include(CTest)
 include(SwiftSupport)
 
-if(CMAKE_VERSION VERSION_LESS 3.16 AND CMAKE_SYSTEM_NAME STREQUAL Windows)
-  set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
-  set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
-else()
-  set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
-  set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
-endif()
+list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules)
 
+set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
+set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+
 set(CMAKE_Swift_MODULE_DIRECTORY ${CMAKE_BINARY_DIR}/swift)
 
 find_package(dispatch CONFIG)