Rework command line handling of build tool (#2373)

In `tools/build.py`:
- For the sake of readability, group CLI arguments as general build
  options, options to control the building of components, and
  component-specific options.
- To prevent duplications, remove the defaults from those CLI
  arguments that correspond to CMake options and have defaults in
  any of the CMakeLists. Should any of the defaults change, they
  will have to be changed at a single place only. (Those options
  that are not set on the command line of `tools/build.py` are not
  passed as options to `cmake` either.)
- Convert `--unittests` and `--doctests` to ON/OFF options like the
  rest of the component switches.
- Touch on some of the help messages of the CLI arguments.

Other changes:
- The change in `--unittests` and `--doctests` is a slightly CLI-
  breaking change of `tools/build.py`. Thus, follow up on this in
  `tools/run-tests.py`.
- Move `ENABLE_ALL_IN_ONE` into `jerry-core` as it is not a general
  option but specific to that component.
- Remove the forcing of `ENABLE_ALL_IN_ONE` for some compilers/
  platforms as it is still an option, not a hard requirement.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

CMakeLists.txt

@@ -54,7 +54,6 @@ set(DOCTESTS                OFF CACHE BOOL "Build doc tests?")
 
 # Optional build settings
 set(BUILD_SHARED_LIBS  OFF CACHE BOOL "Build shared libraries?")
-set(ENABLE_ALL_IN_ONE  OFF CACHE BOOL "Enable all-in-one build?")
 set(ENABLE_LTO         ON  CACHE BOOL "Enable LTO build?")
 set(ENABLE_STRIP       ON  CACHE BOOL "Enable stripping all symbols from release binary?")
 
@@ -77,13 +76,11 @@ endif()
 if("${PLATFORM}" STREQUAL "DARWIN")
   set(JERRY_LIBC         OFF)
   set(JERRY_LIBM         OFF)
-  set(ENABLE_ALL_IN_ONE  ON)
   set(ENABLE_LTO         OFF)
   set(ENABLE_STRIP       OFF)
 
   set(JERRY_LIBC_MESSAGE         " (FORCED BY PLATFORM)")
   set(JERRY_LIBM_MESSAGE         " (FORCED BY PLATFORM)")
-  set(ENABLE_ALL_IN_ONE_MESSAGE  " (FORCED BY PLATFORM)")
   set(ENABLE_LTO_MESSAGE         " (FORCED BY PLATFORM)")
   set(ENABLE_STRIP_MESSAGE       " (FORCED BY PLATFORM)")
 endif()
@@ -97,12 +94,10 @@ endif()
 if(USING_MSVC)
   set(JERRY_LIBC         OFF)
   set(JERRY_LIBM         OFF)
-  set(ENABLE_ALL_IN_ONE  ON)
   set(ENABLE_STRIP       OFF)
 
   set(JERRY_LIBC_MESSAGE         " (FORCED BY COMPILER)")
   set(JERRY_LIBM_MESSAGE         " (FORCED BY COMPILER)")
-  set(ENABLE_ALL_IN_ONE_MESSAGE  " (FORCED BY COMPILER)")
   set(ENABLE_STRIP_MESSAGE       " (FORCED BY COMPILER)")
 endif()
 
@@ -112,7 +107,6 @@ message(STATUS "CMAKE_C_COMPILER_ID         " ${CMAKE_C_COMPILER_ID})
 message(STATUS "CMAKE_SYSTEM_NAME           " ${CMAKE_SYSTEM_NAME})
 message(STATUS "CMAKE_SYSTEM_PROCESSOR      " ${CMAKE_SYSTEM_PROCESSOR})
 message(STATUS "BUILD_SHARED_LIBS           " ${BUILD_SHARED_LIBS})
-message(STATUS "ENABLE_ALL_IN_ONE           " ${ENABLE_ALL_IN_ONE} ${ENABLE_ALL_IN_ONE_MESSAGE})
 message(STATUS "ENABLE_LTO                  " ${ENABLE_LTO} ${ENABLE_LTO_MESSAGE})
 message(STATUS "ENABLE_STRIP                " ${ENABLE_STRIP} ${ENABLE_STRIP_MESSAGE})
 message(STATUS "JERRY_CMDLINE               " ${JERRY_CMDLINE})