Use clonefile(2) in more places

A lot of file copies that we create are not subsequently modified,
especially in the destroot phase. This makes cloning a more efficient
alternative.

* Modified xinstall and 'file copy' Tcl commands to try cloning.
* Created a vendored copy of install(1) that tries cloning.
* Created a thin wrapper around cp(1) that adds the -c flag.
* If the build directory is on a filesystem that supports cloning, the
  configure.install option defaults to our install(1), and the
  directory containing our install and cp commands is added to the
  front of PATH, currently only during the destroot phase.

The code for all of the above is not built on systems that lack
clonefile(2). If cloning fails, everything will fall back to creating
a copy as previously done.

configure

@@ -672,6 +672,7 @@ VENDOR_TCLX_SUBDIR
 VENDOR_DESTROOT
 VENDOR_TCL_INSTALL
 VENDOR_TCL_SUBDIR
+CLONEBIN_PATH
 localstatedir_expanded
 MPCONFIGDIR_EXPANDED
 DARWINTRACE_SIP_WORKAROUND_PATH
@@ -689,6 +690,8 @@ HAVE_STRLCPY
 HAVE_STRLCAT
 HAVE_GETLINE
 HAVE_GETDELIM
+EXTRA_PROGS
+HAVE_CLONEFILE
 HAVE_TIMINGSAFE_BCMP
 HAVE_GETENTROPY
 HAVE_ARC4RANDOM_BUF
@@ -704,7 +707,6 @@ RUNUSR
 DSTGRP
 DSTUSR
 MPCONFIGDIR
-EXTRA_PROGS
 HAVE_FUNCTION_CFNOTIFICATIONCENTERGETDARWINNOTIFYCENTER
 HAVE_FRAMEWORK_IOKIT
 HAVE_FRAMEWORK_SYSTEMCONFIGURATION
@@ -7012,8 +7014,6 @@ printf %s "checking for whether we will build daemondo... " >&6; }
 printf "%s\n" "${result}" >&6; }
 
 
-
-
 # Check for paths
 
 
@@ -7729,6 +7729,17 @@ HAVE_GETENTROPY=$ac_cv_func_getentropy
 HAVE_TIMINGSAFE_BCMP=$ac_cv_func_timingsafe_bcmp
 
 
+# For vendor/install
+HAVE_CLONEFILE=$ac_cv_func_clonefile
+
+# For programs/cp
+if test x$ac_cv_func_clonefile = xyes; then
+EXTRA_PROGS="$EXTRA_PROGS cp"
+ac_config_files="$ac_config_files src/programs/cp/Makefile vendor/install/Makefile"
+
+fi
+
+
 # Check for library functions, replacements are in pextlib1.0/compat/
 ac_fn_c_check_func "$LINENO" "getline" "ac_cv_func_getline"
 if test "x$ac_cv_func_getline" = xyes
@@ -8660,6 +8671,11 @@ eval "macports_libexec_dir=$macports_libexec_dir"
 prefix=$oldprefix
 exec_prefix=$oldexec_prefix
 
+if test x$ac_cv_func_clonefile = xyes; then
+    CLONEBIN_PATH="${macports_libexec_dir}/clonebin"
+fi
+
+
 ## Tcl package
 	mp_fn_var_prepend() {
 		eval "$1=\"$2\$$1\""
@@ -10448,6 +10464,8 @@ do
   case $ac_config_target in
     "src/config.h") CONFIG_HEADERS="$CONFIG_HEADERS src/config.h" ;;
     "src/programs/daemondo/Makefile") CONFIG_FILES="$CONFIG_FILES src/programs/daemondo/Makefile" ;;
+    "src/programs/cp/Makefile") CONFIG_FILES="$CONFIG_FILES src/programs/cp/Makefile" ;;
+    "vendor/install/Makefile") CONFIG_FILES="$CONFIG_FILES vendor/install/Makefile" ;;
     "Doxyfile") CONFIG_FILES="$CONFIG_FILES Doxyfile" ;;
     "Makefile") CONFIG_FILES="$CONFIG_FILES Makefile" ;;
     "Mk/macports.autoconf.mk") CONFIG_FILES="$CONFIG_FILES Mk/macports.autoconf.mk" ;;