Merge pull request swiftlang#35436 from edymtt/separate-modulecache-libdispatch-llbuild-foundation-xctest-5.3

[5.3] Use dedicated modulecache for libdispatch et al.

Author: najacque

utils/build-script-impl

@@ -2075,6 +2075,7 @@ for host in "${ALL_HOSTS[@]}"; do
                     -DCMAKE_BUILD_TYPE:STRING="${LLBUILD_BUILD_TYPE}"
                     -DCMAKE_INSTALL_PREFIX:PATH="$(get_host_install_prefix ${host})"
                     -DCMAKE_Swift_COMPILER:PATH="$(build_directory_bin ${LOCAL_HOST} swift)/swiftc"
+                    -DCMAKE_Swift_FLAGS:STRING="-module-cache-path \"${module_cache}\""
 
                     -DLLBUILD_ENABLE_ASSERTIONS:BOOL=$(true_false "${LLBUILD_ENABLE_ASSERTIONS}")
                     -DLLBUILD_SUPPORT_BINDINGS:=Swift
@@ -2151,6 +2152,7 @@ for host in "${ALL_HOSTS[@]}"; do
                     -DCMAKE_C_COMPILER:PATH="${LLVM_BIN}/clang"
                     -DCMAKE_CXX_COMPILER:PATH="${LLVM_BIN}/clang++"
                     -DCMAKE_Swift_COMPILER:PATH="$(build_directory_bin ${LOCAL_HOST} swift)/swiftc"
+                    -DCMAKE_Swift_FLAGS:STRING="-module-cache-path \"${module_cache}\""
                     -DCMAKE_INSTALL_PREFIX:PATH="$(get_host_install_prefix ${host})"
                     -DCMAKE_INSTALL_LIBDIR:PATH="lib"
 
@@ -2222,6 +2224,7 @@ for host in "${ALL_HOSTS[@]}"; do
                   -DCMAKE_CXX_COMPILER:PATH=${LLVM_BIN}/clang++
                   -DCMAKE_SWIFT_COMPILER:PATH=${SWIFTC_BIN}
                   -DCMAKE_Swift_COMPILER:PATH=${SWIFTC_BIN}
+                  -DCMAKE_Swift_FLAGS:STRING="-module-cache-path \"${module_cache}\""
                   -DCMAKE_INSTALL_PREFIX:PATH=$(get_host_install_prefix ${host})
 
                   ${LIBICU_BUILD_ARGS[@]}
@@ -2265,6 +2268,7 @@ for host in "${ALL_HOSTS[@]}"; do
                     -DCMAKE_CXX_COMPILER:PATH="${LLVM_BIN}/clang++"
                     -DCMAKE_SWIFT_COMPILER:PATH="${SWIFTC_BIN}"
                     -DCMAKE_Swift_COMPILER:PATH="${SWIFTC_BIN}"
+                    -DCMAKE_Swift_FLAGS:STRING="-module-cache-path \"${module_cache}\""
                     -DCMAKE_INSTALL_PREFIX:PATH="$(get_host_install_prefix ${host})"
                     -DCMAKE_INSTALL_LIBDIR:PATH="lib"