Hi,

Patch for supporting DW_AT_calling_convention. This helps GDB identify
the "main" program for languages that do not have a starting subroutine
called "main". The patch also adds a new type flag,
TYPE_FLAG_MAIN_PROGRAM which is set if the type is describing a "main"
entry point. This can be used, for example, in noting a subroutine type
as a FORTRAN PROGRAM.

2002-07-09 Petr Sorfa (petrs@caldera.com)

        *  dwarf2read.c (read_subroutine_type): Expanded to recognize
           the DW_AT_calling_convention DWARF attribute and for
           DW_CC_program set the TYPE_FLAG_MAIN_PROGRAM type flag
           and call set_main_name ().
           (read_partial_die): Now recognizes the
           DW_AT_calling_convention attribute and calls set_main_name().
           Note that TYPE_FLAG_MAIN_PROGRAM type flag is not set, as
           the partial_die might not denote a subroutine type.

        *  gdbtypes.h (TYPE_FLAG_MAIN_PROGRAM): New type flag which
           indicates whether the type denotes a main program subroutine.
           (TYPE_MAIN_PROGRAM): New macro that returns a non-zero value
           if the type describes a main program subroutine.