prog_to_nir: OPCODE_EXP is not nir_op_fexp
prog_to_nir: OPCODE_EXP is not nir_op_fexp

It's a weird thing that provides some values related to 2**x.  It's also
already handled by a case in the switch.

Signed-off-by: Ian Romanick <2b237cafb16dc45038e85df6c85e74e6d899eba9@intel.com>
Reviewed-by: Matt Turner <789b315743a28dd066a4ba1459c35951c291d8a6@gmail.com>
Acked-by: Jason Ekstrand <b186559eaedf698788888c8a2559b4efb4db10d6@intel.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler