Operand of increment/decrement should not be a number
Operand of increment/decrement should not be a number

The patch adds necessary error checking to verify that the operands of
increment decrement operator is not number.

Signed-off-by: Prasad Joshi <d7fbabb3289b145a0f256d6596e2e43e9ecb9986@canopusconsultancy.com>

themperek/iverilog,CastMi/iverilog,CastMi/iverilog,themperek/iverilog,themperek/iverilog,CastMi/iverilog