[SR-9455] extra-cmake-options are not forwarded to CoreFoundation build

[kevints]

Previous ID	SR-9455
Radar	None
Original Reporter	@kevints
Type	Bug

Additional Detail from JIRA

Votes	0
Component/s	Foundation
Labels	Bug, BuildScript, CMake
Assignee	None
Priority	Medium

md5: 04ea53c822f5035afa9614809d12ab0f

Issue Description:

When I invoke build-script with extra-cmake-options they are not forwarded to the CoreFoundation build. This is due to the use of ExternalProject_Add to build CoreFoundation rather than add_subdirectory. I could whitelist the flags I'm trying to pass through (CURL_LIBRARY AND CURL_INCLUDE_DIR) but there's a high risk there are other important flags controlling the CoreFoundation build. Using add_subdirectory instead would allow CoreFoundation and Foundation to share a cache, so that important build settings don't vary between them.

[kevints]

CC @compnerd

[kevints]

I've hacked up a branch that fixes this, I'll clean it up and put up a PR shortly.