Merge pull request swiftlang#22309 from nkcsgexi/dsym-gen-with-release

build-script: teach the script to extract symbols when installing libSyntax parser only.

Author: nkcsgexi

utils/build-presets.ini

@@ -1781,3 +1781,4 @@ build-libparser-only
 swiftsyntax
 verbose-build
 skip-swiftsyntax-swiftside
+darwin-install-extract-symbols

utils/build-script-impl

@@ -3815,29 +3815,39 @@ for host in "${ALL_HOSTS[@]}"; do
             call darwin_install_extract_symbols
         else
             set -x
+            if [ "${BUILD_LIBPARSER_ONLY}" ]; then
+                # We don't have a toolchain so we should install to the specified dir
+                CURRENT_INSTALL_DIR="${INSTALL_DESTDIR}"
+                CURRENT_PREFIX="/."
+            else
+                # If we have a toolchain, use the toolchain install dir.
+                CURRENT_INSTALL_DIR=${host_install_destdir}
+                CURRENT_PREFIX="${TOOLCHAIN_PREFIX}"
+            fi
+
             # Copy executables and shared libraries from the `host_install_destdir` to
             # INSTALL_SYMROOT and run dsymutil on them.
-            (cd "${host_install_destdir}" &&
-             find ./"${TOOLCHAIN_PREFIX}" -perm -0111 -type f -print | cpio --insecure -pdm "${INSTALL_SYMROOT}")
+            (cd "${CURRENT_INSTALL_DIR}" &&
+             find ./"${CURRENT_PREFIX}" -perm -0111 -type f -print | cpio --insecure -pdm "${INSTALL_SYMROOT}")
 
             # Run dsymutil on executables and shared libraries.
             #
             # Exclude shell scripts.
             (cd "${INSTALL_SYMROOT}" &&
-             find ./"${TOOLCHAIN_PREFIX}" -perm -0111 -type f -print | \
+             find ./"${CURRENT_PREFIX}" -perm -0111 -type f -print | \
                grep -v crashlog.py | \
                grep -v symbolication.py | \
                xargs -n 1 -P ${BUILD_JOBS} $(xcrun_find_tool dsymutil))
 
             # Strip executables, shared libraries and static libraries in
             # `host_install_destdir`.
-            find "${host_install_destdir}${TOOLCHAIN_PREFIX}/" \
+            find "${CURRENT_INSTALL_DIR}${CURRENT_PREFIX}/" \
               '(' -perm -0111 -or -name "*.a" ')' -type f -print | \
               xargs -n 1 -P ${BUILD_JOBS} $(xcrun_find_tool strip) -S
 
             # Codesign dylibs after strip tool
             # rdar://45388785
-            find "${host_install_destdir}${TOOLCHAIN_PREFIX}/" \
+            find "${CURRENT_INSTALL_DIR}${CURRENT_PREFIX}/" \
               '(' -name "*.dylib" ')' -type f -print | \
               xargs -n 1 -P ${BUILD_JOBS} $(xcrun_find_tool codesign) -f -s -