build: cmake fixes

- add EXTERNALPROJECT_OPTIONS variable to main build
- use `REQUIRED` keyword for IWYU.
- remove check_c_compiler_flag checks when `ENABLE_COMPILER_SUGGESTIONS`
  is `ON`. If we explicitly enable it then we probably want it to give
  an error if it doesn't exist, rather than silently skip it.
- Move dependency interface libraries to their find module and use them
  as a pseudo-imported target.
- Remove BUSTED_OUTPUT_TYPE. It's not used and we can reintroduce it
  again if something similar is needed.
- Use LINK_OPTIONS intead of LINK_FLAGS when generating the `--version`
  output.

cmake.deps/CMakeLists.txt

@@ -34,18 +34,16 @@ set(DEPS_INCLUDE_FLAGS "-I${DEPS_INSTALL_DIR}/include -I${DEPS_INSTALL_DIR}/incl
 
 option(USE_BUNDLED "Use bundled dependencies." ON)
 
-option(USE_BUNDLED_UNIBILIUM "Use the bundled unibilium." ${USE_BUNDLED})
-option(USE_BUNDLED_LIBVTERM "Use the bundled libvterm." ${USE_BUNDLED})
 option(USE_BUNDLED_LIBUV "Use the bundled libuv." ${USE_BUNDLED})
-option(USE_BUNDLED_MSGPACK "Use the bundled msgpack." ${USE_BUNDLED})
+option(USE_BUNDLED_LIBVTERM "Use the bundled libvterm." ${USE_BUNDLED})
+option(USE_BUNDLED_LPEG "Use the bundled lpeg." ${USE_BUNDLED})
+option(USE_BUNDLED_LUA "Use the bundled version of lua." OFF)
 option(USE_BUNDLED_LUAJIT "Use the bundled version of luajit." ${USE_BUNDLED})
 option(USE_BUNDLED_LUV "Use the bundled version of luv." ${USE_BUNDLED})
-option(USE_BUNDLED_LPEG "Use the bundled lpeg." ${USE_BUNDLED})
-#XXX(tarruda): Lua is only used for debugging the functional test client, don't
-# build it unless explicitly requested
-option(USE_BUNDLED_LUA "Use the bundled version of lua." OFF)
-option(USE_BUNDLED_TS_PARSERS "Use the bundled treesitter parsers." ${USE_BUNDLED})
+option(USE_BUNDLED_MSGPACK "Use the bundled msgpack." ${USE_BUNDLED})
 option(USE_BUNDLED_TS "Use the bundled treesitter runtime." ${USE_BUNDLED})
+option(USE_BUNDLED_TS_PARSERS "Use the bundled treesitter parsers." ${USE_BUNDLED})
+option(USE_BUNDLED_UNIBILIUM "Use the bundled unibilium." ${USE_BUNDLED})
 
 if(USE_BUNDLED AND MSVC)
   option(USE_BUNDLED_GETTEXT "Use the bundled version of gettext." ON)

cmake.deps/cmake/BuildLuajit.cmake

@@ -7,10 +7,6 @@ function(BuildLuajit)
     "TARGET"
     "CONFIGURE_COMMAND;BUILD_COMMAND;INSTALL_COMMAND;DEPENDS"
     ${ARGN})
-  if(NOT _luajit_CONFIGURE_COMMAND AND NOT _luajit_BUILD_COMMAND
-        AND NOT _luajit_INSTALL_COMMAND)
-    message(FATAL_ERROR "Must pass at least one of CONFIGURE_COMMAND, BUILD_COMMAND, INSTALL_COMMAND")
-  endif()
   if(NOT _luajit_TARGET)
     set(_luajit_TARGET "luajit")
   endif()

cmake.deps/cmake/BuildTreesitter.cmake

@@ -2,7 +2,6 @@ ExternalProject_Add(treesitter
   URL ${TREESITTER_URL}
   URL_HASH SHA256=${TREESITTER_SHA256}
   DOWNLOAD_DIR ${DEPS_DOWNLOAD_DIR}/treesitter
-  INSTALL_DIR ${DEPS_INSTALL_DIR}
   PATCH_COMMAND ${CMAKE_COMMAND} -E copy
     ${CMAKE_CURRENT_SOURCE_DIR}/cmake/TreesitterCMakeLists.txt
     ${DEPS_BUILD_DIR}/src/treesitter/CMakeLists.txt

cmake.deps/cmake/MarkdownParserCMakeLists.txt

@@ -6,7 +6,6 @@ endif()
 project(${PARSERLANG} C)
 
 add_compile_options(-w)
-set(CMAKE_C_STANDARD 99)
 
 add_library(markdown MODULE
 tree-sitter-markdown/src/parser.c