[SR-11899] ALL_BUILD fails due to wrong path to cmark (looking for Debug, not Release)

[swift-ci]

Previous ID	SR-11899
Radar	rdar://problem/57711779
Original Reporter	ajo (JIRA User)
Type	Bug

Additional Detail from JIRA

| | | |------------------|-----------------| |Votes | 0 | |Component/s | Compiler | |Labels | Bug | |Assignee | None | |Priority | Medium | md5: 1c578149b4d450bceadf4343fa992a89

Issue Description:

`./utils/build-script -x -R` then building the ALL_BUILD scheme fails due to it looking for cmark at `/build/Xcode-ReleaseAssert/cmark-macosx-x86_64/src/Debug` instead of `/build/Xcode-ReleaseAssert/cmark-macosx-x86_64/src/Release`

[beccadax]

@swift-ci create