When parsing a descriptor, it is useful to be able to check whether a
string begins with a substring without consuming that substring as
another function such as Func() will be used later which requires that
substring to be present at the beginning.
Specifically, for MuSig2, this modified Const will be used to determine
whether a an expression begins with "musig(" before a subsequent
Func("musig", ...) is used.
Historically, the headers have been bumped some time after a file has
been touched. Do it now to avoid having to touch them again in the
future for that reason.
-BEGIN VERIFY SCRIPT-
sed -i --regexp-extended 's;( 20[0-2][0-9])(-20[0-2][0-9])? The Bitcoin Core developers;\1-present The Bitcoin Core developers;g' $( git show --pretty="" --name-only HEAD~1 )
-END VERIFY SCRIPT-
Move miniscript / descriptor script parsing functions out of util library so
they are not a dependency of the kernel.
There are no changes to code or behavior.