Merge pull request swiftlang#8645 from apple/update_preset_to_reconfig_once

[build-script] Add skip reconfigure flag to build-script-impl

Author: shahmishal

utils/build-script-impl

@@ -99,6 +99,7 @@ KNOWN_SETTINGS=(
     installable-package         ""               "the path to the archive of the installation directory"
     test-installable-package    ""               "whether to run post-packaging tests on the produced package"
     reconfigure                 ""               "force a CMake configuration run even if CMakeCache.txt already exists"
+    skip-reconfigure            ""               "set to skip reconfigure"
     swift-primary-variant-sdk   ""               "default SDK for target binaries"
     swift-primary-variant-arch  ""               "default arch for target binaries"
     skip-build-cmark            ""               "set to skip building CommonMark"
@@ -943,6 +944,10 @@ if [[ "${CROSS_COMPILE_HOSTS}" ]]; then
     SKIP_BUILD_COMPILER_RT=1
 fi
 
+if [[ "${SKIP_RECONFIGURE}" ]]; then
+    RECONFIGURE=""
+fi
+
 # WORKSPACE, BUILD_DIR and INSTALLABLE_PACKAGE must be absolute paths
 case "${WORKSPACE}" in
     /*) ;;