selfupdate: attempt to force a native build on arm64

See: https://trac.macports.org/ticket/70512

src/macports1.0/selfupdate.tcl

@@ -454,6 +454,7 @@ proc selfupdate::install {source} {
  # Choose a sane compiler and SDK
  set cc_arg {}
  set sdk_arg {}
+ set arch_arg {}
  set jobs [macports::get_parallel_jobs yes]
  if {$os_platform eq "darwin"} {
  catch {exec /usr/bin/cc 2>@1} output
@@ -488,12 +489,16 @@ proc selfupdate::install {source} {
  }
  }
  }
+ if {$os_major >= 20 && ![catch {sysctl sysctl.proc_translated} translated] && $translated} {
+ # Force a native build
+ set arch_arg "/usr/bin/arch -arm64 /usr/bin/env "
+ }
  }
 
  # do the actual configure, build and installation of new base
  ui_msg "$ui_prefix Installing new MacPorts release in $prefix as ${owner}:${group}; permissions ${perms}"
  macports_try -pass_signal {
- system -W $source "${cc_arg}${sdk_arg}./configure $configure_args_string && ${sdk_arg}make -j${jobs} SELFUPDATING=1 && make install SELFUPDATING=1"
+ system -W $source "${arch_arg}${cc_arg}${sdk_arg}./configure $configure_args_string && ${arch_arg}${sdk_arg}make -j${jobs} SELFUPDATING=1 && ${arch_arg}make install SELFUPDATING=1"
  } on error {eMessage} {
  error "Error installing new MacPorts base: $eMessage"
  }