cobol: Introduce vendor-compatibility layer as user-defined functions.

cobol: Introduce vendor-compatibility layer as user-defined functions.

Install COBOL UDFs in a target directory that includes the GCC version
in its path, to permit side-by-side installation. Support compat
library with COBOL POSIX bindings; support those binding with C
functions in libgcobol as needed.

Changes to the compiler to support POSIX binding and testing.

Include developer conveniences -- Makefiles, bin/ and t/ directories --
to ensure UDFs compile and return reasonable results.  These are
not installed and do not affect how libgcobol is built.

gcc/cobol/ChangeLog:

	* cdf.y: Install literals in symbol table.
	* genapi.cc (parser_alphabet): Use std::string for currency.
	(initialize_the_data): Rely on constructor.
	(parser_file_add): Better #pragma message.
	(parser_exception_file): Return early if not generating code.
	* parse.y: Allow library programs to act as functions.
	* parse_ante.h (dialect_proscribed): Standardize message.
	(intrinsic_call_2): Correct s/fund/func/ misspelling.
	* scan.l: Comment.
	* symbols.cc (symbols_update): Add unreachable assertion.
	(symbol_field_parent_set): Reduce error to debug message.
	(cdf_literalize): Declare.
	(symbol_table_init): Insert CDF constants as literals.
	* symbols.h (cbl_dialect_str): Provide string values for enum.
	(is_working_storage): Remove function.
	(struct cbl_field_data_t): Add manhandle_initial for Numeric Edited.
	(struct cbl_field_t): Initialize name to zeros.
	(struct cbl_section_t): Delete unused attr() function.
	(symbol_unique_index): Declare.
	* token_names.h: Regenerate.
	* util.cc (cdf_literalize): Construct a cbl_field_t from a CDF literal.
	(symbol_unique_index): Supply "globally" unique number for a program.

libgcobol/ChangeLog:

	* Makefile.am: Move UDF-support to posix/shim, add install targets
	* Makefile.in: Regenerate
	* charmaps.cc (__gg__currency_signs): Use std::string.
	* charmaps.h: Include string and vector headers.
	(class charmap_t): Use std::string and vector for currency.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Check for libxml2.
	* intrinsic.cc (numval_c): Constify.
	* libgcobol.cc (struct program_state): Use std::string and vector.
	(__gg__inspect_format_2): Add debug messages.
	* libgcobol.h (__gg__get_default_currency_string): Constify.
	* valconv.cc (expand_picture): Use std::string and vector.
	(__gg__string_to_numeric_edited): Use std::string and vector.
	(__gg__currency_sign_init): Use std::string and vector.
	(__gg__currency_sign): Use std::string and vector.
	* xmlparse.cc (xml_push_parse): Reformat.
	* posix/stat.cc: Removed.
	* posix/stat.h: Removed.
	* .gitignore: New file.
	* compat/README.md: New file.
	* compat/lib/gnu/CBL_ALLOC_MEM.cbl: New file.
	* compat/lib/gnu/CBL_CHECK_FILE_EXIST.cbl: New file.
	* compat/lib/gnu/CBL_DELETE_FILE.cbl: New file.
	* compat/lib/gnu/CBL_FREE_MEM.cbl: New file.
	* compat/t/Makefile: New file.
	* compat/t/smoke.cbl: New file.
	* posix/README.md: New file.
	* posix/bin/Makefile: New file for UDF-developer.
	* posix/bin/headers: New file.
	* posix/bin/scrape.awk: New file.
	* posix/bin/sizeofs.c: New file.
	* posix/bin/udf-gen: New file.
	* posix/cpy/posix-errno.cbl: New file.
	* posix/cpy/statbuf.cpy: New file.
	* posix/cpy/tm.cpy: New file.
	* posix/errno.cc: Removed.
	* posix/localtime.cc: Removed.
	* posix/shim/stat.cc: New file.
	* posix/shim/stat.h: New file.
	* posix/t/Makefile: New file.
	* posix/t/errno.cbl: New file.
	* posix/t/exit.cbl: New file.
	* posix/t/localtime.cbl: New file.
	* posix/t/stat.cbl: New file.
	* posix/tm.h: Removed.
	* posix/udf/posix-exit.cbl: New file.
	* posix/udf/posix-localtime.cbl: New file.
	* posix/udf/posix-mkdir.cbl: New file.
	* posix/udf/posix-stat.cbl: New file.
	* posix/udf/posix-unlink.cbl: New file.