build: add CMake based build system

GYP has been replaced with GN for Chromium.  Migrate to CMake rather
than GN as it is simpler.  This allows building for Windows ARM64 as
well.

src/CMakeLists.txt

@@ -0,0 +1,103 @@
+
+cmake_minimum_required(VERSION 3.20)
+
+project(WinPTY
+  VERSION 0.4.4
+  LANGUAGES CXX)
+
+# Output Locations
+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)
+
+# Global Macros
+add_compile_definitions(UNICODE)
+add_compile_definitions(_UNICODE)
+add_compile_definitions(NOMINMAX)
+
+execute_process(COMMAND git rev-parse HEAD
+  WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
+  OUTPUT_VARIABLE GIT_REVISION
+  OUTPUT_STRIP_TRAILING_WHITESPACE)
+if(NOT GIT_REVISION)
+  set(GIT_REVISION none)
+endif()
+
+file(WRITE ${CMAKE_BINARY_DIR}/gen/GenVersion.h "// AUTO-GENERATED BY CMake
+const char GenVersion_Version[] = \"${PROJECT_VERSION}\";
+const char GenVersion_Commit[] = \"${GIT_REVISION}\";
+")
+
+include_directories(${CMAKE_BINARY_DIR}/gen)
+
+add_executable(winpty-agent
+  agent/Agent.cc
+  agent/AgentCreateDesktop.cc
+  agent/ConsoleFont.cc
+  agent/ConsoleInput.cc
+  agent/ConsoleInputReencoding.cc
+  agent/ConsoleLine.cc
+  agent/DebugShowInput.cc
+  agent/DefaultInputMap.cc
+  agent/EventLoop.cc
+  agent/InputMap.cc
+  agent/LargeConsoleRead.cc
+  agent/NamedPipe.cc
+  agent/Scraper.cc
+  agent/Terminal.cc
+  agent/Win32Console.cc
+  agent/Win32ConsoleBuffer.cc
+  agent/main.cc
+  shared/BackgroundDesktop.cc
+  shared/Buffer.cc
+  shared/DebugClient.cc
+  shared/GenRandom.cc
+  shared/OwnedHandle.cc
+  shared/StringUtil.cc
+  shared/WindowsSecurity.cc
+  shared/WindowsVersion.cc
+  shared/WinptyAssert.cc
+  shared/WinptyException.cc
+  shared/WinptyVersion.cc)
+target_compile_definitions(winpty-agent PRIVATE
+  WINPTY_AGENT_ASSERT)
+target_include_directories(winpty-agent PRIVATE
+  include)
+target_link_libraries(winpty-agent PRIVATE
+  advapi32
+  shell32
+  user32)
+
+add_library(winpty SHARED
+  libwinpty/AgentLocation.cc
+  libwinpty/winpty.cc
+  shared/BackgroundDesktop.cc
+  shared/Buffer.cc
+  shared/DebugClient.cc
+  shared/GenRandom.cc
+  shared/OwnedHandle.cc
+  shared/StringUtil.cc
+  shared/WindowsSecurity.cc
+  shared/WindowsVersion.cc
+  shared/WinptyAssert.cc
+  shared/WinptyException.cc
+  shared/WinptyVersion.cc)
+target_include_directories(winpty PRIVATE
+  include)
+target_compile_definitions(winpty PRIVATE
+  COMPILING_WINPTY_DLL)
+target_link_libraries(winpty PRIVATE
+  advapi32
+  user32)
+
+add_executable(winpty-debugserver
+  debugserver/DebugServer.cc
+  shared/DebugClient.cc
+  shared/OwnedHandle.cc
+  shared/StringUtil.cc
+  shared/WindowsSecurity.cc
+  shared/WindowsVersion.cc
+  shared/WinptyAssert.cc
+  shared/WinptyException.cc)
+target_link_libraries(winpty-debugserver PRIVATE
+  advapi32)