Add option to configure Ninja link job pool for CMake's own binaries

Create an undocumented `CMake_JOB_POOL_LINK_BIN` option that builders
can set to avoid linking too many of our binaries at once.

Source/CMakeLists.txt

@@ -1193,6 +1193,11 @@ if(WIN32)
   endforeach()
 endif()
 
+if(CMake_JOB_POOL_LINK_BIN)
+  set_property(TARGET ${_tools} PROPERTY JOB_POOL_LINK "link-bin")
+  set_property(GLOBAL APPEND PROPERTY JOB_POOLS "link-bin=${CMake_JOB_POOL_LINK_BIN}")
+endif()
+
 # Install tools
 
 foreach(_tool ${_tools})

Source/CursesDialog/CMakeLists.txt

@@ -34,5 +34,9 @@ else()
   target_link_libraries(ccmake cmForm)
 endif()
 
+if(CMake_JOB_POOL_LINK_BIN)
+  set_property(TARGET ccmake PROPERTY JOB_POOL_LINK "link-bin")
+endif()
+
 CMake_OPTIONAL_COMPONENT(ccmake)
 install(TARGETS ccmake DESTINATION ${CMAKE_BIN_DIR} ${COMPONENT})

Source/QtDialog/CMakeLists.txt

@@ -178,6 +178,10 @@ if(WIN32)
   target_sources(cmake-gui PRIVATE $<TARGET_OBJECTS:CMakeVersion>)
 endif()
 
+if(CMake_JOB_POOL_LINK_BIN)
+  set_property(TARGET cmake-gui PROPERTY JOB_POOL_LINK "link-bin")
+endif()
+
 # cmake-gui has not been updated for `include-what-you-use`.
 # Block the tool until this is done.
 set_target_properties(cmake-gui PROPERTIES