Runtimes: rename Core/core to Core/Core (uppercase C) so it appears...

higher in case sensitive directory listings (like GitHub).

This will ease checking for stdlib code on small screens without needing
to scroll.

Git will not take care of adjusting the case if the folder contains
untracked files (which is the case after syncing the source from the
stdlib fodler) -- to account for this, have the resync script perform
the rename if need be, so we don't have errors when invoking the
Runtime build system (since CMake considers paths as case sensitive
regardless of the underlying file system).

Addresses rdar://164195263

Author: edymtt

Runtimes/Core/CMakeLists.txt

@@ -206,7 +206,7 @@ add_subdirectory(Demangling)
 add_subdirectory(Threading)
 add_subdirectory(runtime)
 add_subdirectory(stubs)
-add_subdirectory(core)
+add_subdirectory(Core)
 if(SwiftCore_ENABLE_COMMANDLINE_SUPPORT)
   add_subdirectory(CommandLineSupport)
 endif()

Runtimes/Core/core/CMakeLists.txt renamed to Runtimes/Core/Core/CMakeLists.txt

@@ -86,7 +86,6 @@ set(CoreLibs
   CompatibilityOverride
   stubs
   CommandLineSupport
-  core
   SwiftOnoneSupport
   RemoteInspection
   SwiftRemoteMirror
@@ -97,6 +96,20 @@ foreach(library ${CoreLibs})
   copy_library_sources(${library} "public" "Core")
 endforeach()
 
+# copying Core/core separately, so we can amend the case of the target folders
+# on case insensitive file systems
+if(IS_READABLE "${CMAKE_CURRENT_LIST_DIR}/Core/core")
+  # If we can see the old lower case name, it means that Git did not perform the rename
+  # because we have untracked content (likely the sources from the stdlib)
+  # Perform the rename now so that CMake is able to find the folder (since it seems
+  # to be always case sensitive)
+  message(STATUS "Renaming ${CMAKE_CURRENT_LIST_DIR}/Core/core (lowercase) to ${CMAKE_CURRENT_LIST_DIR}/Core/Core (uppercase)")
+  file(RENAME "${CMAKE_CURRENT_LIST_DIR}/Core/core" "${CMAKE_CURRENT_LIST_DIR}/Core/core.casechange")
+  file(RENAME "${CMAKE_CURRENT_LIST_DIR}/Core/core.casechange" "${CMAKE_CURRENT_LIST_DIR}/Core/Core")
+endif()
+copy_library_sources("" "public/core" "Core/Core")
+
+
 message(STATUS "plist[${StdlibSources}/Info.plist.in] -> Core/Info.plist.in")
 copy_files("" "Core" FILES "Info.plist.in")