Merge pull request #18653 from JohnCoatesOSS/pkg_config-clobber-fix

Author: swift-ci

utils/build-script-impl

@@ -2588,7 +2588,7 @@ for host in "${ALL_HOSTS[@]}"; do
 
                 # Set the PKG_CONFIG_PATH so that core-foundation can find the libraries and
                 # header files
-                export PKG_CONFIG_PATH="${ICU_TMPLIBDIR}/pkgconfig"
+                export PKG_CONFIG_PATH="${ICU_TMPLIBDIR}/pkgconfig:${PKG_CONFIG_PATH}"
                 swift_cmake_options=(
                     "${swift_cmake_options[@]}"
                     -DSWIFT_${SWIFT_HOST_VARIANT_SDK}_${SWIFT_HOST_VARIANT_ARCH}_ICU_UC_INCLUDE:STRING="${ICU_TMPINSTALL}/include"