Backport using Tcl_GetErrorLine with Tcl8.6

Change-Id: I82150869b1f473b6c56e56167aece5e73089d7bb
Let macro find TclTk version 8.6

Change-Id: Iaf16f371c9e8767bd85f155e863aa92229234abe
Update the TclTk internal files for 8.6

Change-Id: I2af0a113a8080fa17fb8feb0114040739af849bb
Merge release-tcl86_update into master-tcl86_update

Change-Id: I259da74b8cfe4bca3e6d616caac2464f2b46455a
Merge topic 'master-tcl86_update' into master

1b1d6172 Merge release-tcl86_update into master-tcl86_update
4eed633d Update the TclTk internal files for 8.6
58467677 Let macro find TclTk version 8.6
df4daa34 Backport using Tcl_GetErrorLine with Tcl8.6