Merge pull request #40250 from cwakamo/eng/PR-85511438-treat-Playgrounds-trains-like-Xcode-trains

[CMake] Also treat builds in Playgrounds trains as "Xcode" builds.

This addresses <rdar://problem/85511438>.

Author: cwakamo

include/swift/Runtime/CMakeLists.txt

@@ -2,7 +2,7 @@
 set(SWIFT_BNI_OS_BUILD FALSE)
 set(SWIFT_BNI_XCODE_BUILD FALSE)
 if(DEFINED ENV{RC_XBS})
-  if(NOT DEFINED ENV{RC_XCODE} OR NOT "$ENV{RC_XCODE}")
+  if((NOT DEFINED ENV{RC_XCODE} OR NOT "$ENV{RC_XCODE}") AND (NOT DEFINED ENV{RC_PLAYGROUNDS} OR NOT "$ENV{RC_PLAYGROUNDS}"))
     set(SWIFT_BNI_OS_BUILD TRUE)
   else()
     set(SWIFT_BNI_XCODE_BUILD TRUE)