[RFA] lib/gdb.exp: check skip_cplus_tests target info

[Nick Duffek]

On 17-Nov-2000, Fernando Nasser wrote:

>I wonder if this is really board specific.

No, I agree that it's not.  But right now, the skip_cplus_tests procedure
assumes that it is:

  proc skip_cplus_tests {} {
      if { [istarget "d10v-*-*"] } {
          return 1
      }
      if { [istarget "h8300-*-*"] } {
          return 1
      }
      return 0
  }

I wanted a way to skip C++ tests without adding platform-dependent code to
platform-independent sources.  So, I changed skip_cplus_tests to support
lines like the following in board description files:

  set board_info($board,gdb,skip_cplus_tests) 1

I modeled my change on the use of [target_info exists gdb,skip_float_tests]
in various scripts.  Is there a better way?

Nick