systemtap.context/num_args.{tcl,stp}

[Jim Keniston]

Today I checked in a pass-5 test of the relatively new *_arg(n)
functions.  These functions provide access to a probed function's args
by number (e.g., for dwarfless probing) rather than by name.  This test
should pass on powerpc*, i386, and x86_64; but should fail on
architectures that haven't implemented these functions.

The functions are described in stapfuncs.5.in, and are implemented (so
far) in tapset/$arch/registers.stp -- with some help from
runtime/regs.c.

Jim

*in code that includes the fix for PR #6601