cobol: Improve MOVE BINARY/COMP-5 to PACKED-DECIMAL and NUMERIC-DISPLAY

cobol: Improve MOVE BINARY/COMP-5 to PACKED-DECIMAL and NUMERIC-DISPLAY

These are more efficient algorithms for converting binary values to
packed-decimal and zoned decimal byte strings.  There is also an
improved routine that generates GENERIC to do COBOL rounding during
such moves.

gcc/cobol/ChangeLog:

	* gengen.cc (gg_abs): Use fold_build1().
	* genutil.cc (scale_and_round): Remove function.
	(round_this_value): New function for rounding.
	* genutil.h (scale_and_round): Remove function.
	(round_this_value): New declaration.
	* move.cc (cobol_wider_type_with_x_signedness): New function.
	(mh_binary_to_numdisp): Faster routine.
	(mh_binary_to_packed): Faster routine.
	(move_helper): Use the faster routines.

libgcobol/ChangeLog:

	* charmaps.cc (__gg__miconverter): Use table instead of a map.
	(__gg__get_charmap): Likewise.
	* charmaps.h (ebcdic_zero): New constant.
	(ebcdic_plus): Likewise.
	(ebcdic_minus): Likewise.
	* encodings.h (enum cbl_encoding_t): Guardrail for table.
	(ASCII_e): Remove trailing spaces.
	* stringbin.cc (string_from_combined): Improved routine.
	(defined): Likewise.
	(FALLTHROUGH): Likewise.
	(uint_to_8_digits): Improve speed.
	(__gg__binary_to_string_ascii): Likewise.
	(binary_to_string): Likewise.
	(__gg__binary_to_string_ebcdic): Likewise.
	(__gg__binary_to_string_encoded): Likewise.
	(packed_from_combined): Likewise.
	(__gg__binary_to_packed): Likewise.
	(__gg__packed_to_binary): Likewise.

gcc/testsuite/ChangeLog:

	* cobol.dg/group1/simple-classes.cob:
	* cobol.dg/group1/simple-if.cob:
	* cobol.dg/group2/Rounding_from_BINARY_signable_and_negative.cob: New test.
	* cobol.dg/group2/Rounding_from_BINARY_signable_and_negative.out: New test.
	* cobol.dg/group2/Rounding_from_BINARY_signable_and_positive.cob: New test.
	* cobol.dg/group2/Rounding_from_BINARY_signable_and_positive.out: New test.
	* cobol.dg/group2/Rounding_from_BINARY_unsignable.cob: New test.
	* cobol.dg/group2/Rounding_from_BINARY_unsignable.out: New test.