CMake: SwiftCore: Get Slabs building

This patch adds slabs to the new stdlib build system.

Author: etcwilde

Runtimes/Core/CMakeLists.txt

@@ -152,6 +152,8 @@ add_compile_options(
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature FreestandingMacros>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature BitwiseCopyable>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature Extern>"
+  "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature ValueGenerics>"
+  "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature AddressableParameters>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-Xfrontend -enable-experimental-concise-pound-file>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-Xfrontend -enable-lexical-lifetimes=false>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-Xfrontend -disable-implicit-concurrency-module-import>"

Runtimes/Core/core/CMakeLists.txt

@@ -145,6 +145,7 @@ add_library(swiftCore
   SetVariant.swift
   ShadowProtocols.swift
   Shims.swift
+  Slab.swift
   Slice.swift
   SmallString.swift
   Sort.swift