[CMake] Enable StringProcessing build

Enable building the regex parser as part of the new runtime build steps.

Author: etcwilde

CMakeLists.txt

@@ -1627,7 +1627,7 @@ if(SWIFT_ENABLE_NEW_RUNTIME_BUILD)
 
         DEPENDS PopulateRuntimeSourceDir
         CMAKE_ARGS
-          -DCMAKE_INSTALL_LIBDIR:FILEPATH=lib/swift/${SWIFT_SDK_${sdk}_LIB_SUBDIR}/${arch}
+          -DCMAKE_INSTALL_LIBDIR:FILEPATH=lib
           # Compiler will see mismatched swift modules and fail initial checks
           -DCMAKE_Swift_COMPILER_WORKS:BOOLEAN=YES
           -DBUILD_SHARED_LIBS:BOOLEAN=YES # TODO: Make this configurable
@@ -1643,12 +1643,32 @@ if(SWIFT_ENABLE_NEW_RUNTIME_BUILD)
           -DCMAKE_CXX_COMPILER_TARGET:STRING=${stdlib_target_triple}
           -DCMAKE_COLOR_DIAGNOSTICS:BOOLEAN=${CMAKE_COLOR_DIAGNOSTICS}
           -DCMAKE_MAKE_PROGRAM=${CMAKE_MAKE_PROGRAM}
-          -DSwiftCore_PLATFORM_SUBDIR=${SWIFT_SDK_${sdk}_LIB_SUBDIR}
-          -DSwiftCore_ARCH_SUBDIR=${arch}
+          -DSwiftCore_INSTALL_NESTED_SUBDIR=YES
           -DSwiftCore_ENABLE_CONCURRENCY=YES)
       if(NOT ${CMAKE_CROSSCOMPILING})
-        add_dependencies("${stdlib_target}" swift-frontend)
+        add_dependencies("${stdlib_target}-core" swift-frontend)
       endif()
+
+      ExternalProject_Get_Property("${stdlib_target}-core" INSTALL_DIR)
+
+      ExternalProject_Add("${stdlib_target}-StringProcessing"
+        SOURCE_DIR
+          "${CMAKE_CURRENT_SOURCE_DIR}/Runtimes/Supplemental/StringProcessing"
+        DEPENDS "${stdlib_target}-core"
+        INSTALL_DIR "${INSTALL_DIR}"
+        INSTALL_COMMAND "" # No install story set up yet
+        CMAKE_ARGS
+          -DBUILD_SHARED_LIBS=YES
+          -DCMAKE_BUILD_TYPE:STRING=${CMAKE_BUILD_TYPE}
+          -DCMAKE_INSTALL_PREFIX:FILEPATH=${INSTALL_DIR}
+          -DCMAKE_Swift_COMPILER:FILEPATH=$<IF:$<BOOL:${CMAKE_CROSSCOMPILING}>,${CMAKE_Swift_COMPILER},$<PATH:REPLACE_FILENAME,$<TARGET_FILE:swift-frontend>,swiftc>>
+          -DCMAKE_C_COMPILER:FILEPATH=${CMAKE_C_COMPILER}
+          -DCMAKE_CXX_COMPILER:FILEPATH=${CMAKE_CXX_COMPILER}
+          -DCMAKE_Swift_COMPILER_TARGET:STRING=${stdlib_target_triple}
+          -DCMAKE_C_COMPILER_TARGET:STRING=${stdlib_target_triple}
+          -DCMAKE_CXX_COMPILER_TARGET:STRING=${stdlib_target_triple}
+          -DCMAKE_COLOR_DIAGNOSTICS:BOOLEAN=${CMAKE_COLOR_DIAGNOSTICS}
+          -DCMAKE_MAKE_PROGRAM=${CMAKE_MAKE_PROGRAM})
     endforeach()
   endforeach()
 endif()