vendor/bc: import version 6.3.1

This version adds a command to dc to query whether extended registers
are enabled or not.

(cherry picked from commit 61e1a12bb6c3bfdb0a4e499c88e8eaa2b548e427)

contrib/bc: uodate to version 6.2.4

This update contains only documentation changes (new main repository
URL and changed mail address of the program author) and changes to
the build system that do not affect the FreeBSD base system build.

MFC after: 3 days

contrib/bc: merge from vendor release 6.2.2

This update fixes a few issues in history editing and the processing
of the "quit" function. The "quit" function will no longer cause bc
to exit when encountered in a script file (before any command from
the script has been executed).

New functions is_number(), is_string return 1 if the passed argument
is a number resp. a string. The asciify() function has been extended
to support the conversion of an array of numbers into a string.

Merge commit '1a63323d17fedb05b6962853e821c9d7c6b9853e'

usr.bin/ghä-bc, contrib/bc: update to version 5.0.0

Merge commit 2f57ecae4b98e76e5d675563785a7e6c59c868c4

This is a new major release with a number of changes and extensions:

- Limited the number of temporary numbers and made the space for them
static so that allocating more space for them cannot fail.
- Allowed integers with non-zero scale to be used with power, places,
and shift operators.
- Added greatest common divisor and least common multiple to lib2.bc.
- Made bc and dc UTF-8 capable.
- Added the ability for users to have bc and dc quit on SIGINT.
- Added the ability for users to disable prompt and TTY mode by
environment variables.
- Added the ability for users to redefine keywords.
- Added dc's modular exponentiation and divmod to bc.
- Added the ability to assign strings to variables and array elements
and pass them to functions in bc.
- Added dc's asciify command and stream printing to bc.
- Added bitwise and, or, xor, left shift, right shift, reverse,
left rotate, right rotate, and mod functions to lib2.bc.
- Added the functions s2u(x) and s2un(x,n), to lib2.bc.

MFC after: 1 week

usr.bin/ghä-bc, contrib/bc: update to version 5.0.0

Merge commit 2f57ecae4b98e76e5d675563785a7e6c59c868c4

This is a new major release with a number of changes and extensions:

- Limited the number of temporary numbers and made the space for them
static so that allocating more space for them cannot fail.
- Allowed integers with non-zero scale to be used with power, places,
and shift operators.
- Added greatest common divisor and least common multiple to lib2.bc.
- Made bc and dc UTF-8 capable.
- Added the ability for users to have bc and dc quit on SIGINT.
- Added the ability for users to disable prompt and TTY mode by
environment variables.
- Added the ability for users to redefine keywords.
- Added dc's modular exponentiation and divmod to bc.
- Added the ability to assign strings to variables and array elements
and pass them to functions in bc.
- Added dc's asciify command and stream printing to bc.
- Added bitwise and, or, xor, left shift, right shift, reverse,
left rotate, right rotate, and mod functions to lib2.bc.
- Added the functions s2u(x) and s2un(x,n), to lib2.bc.

MFC after: 1 week