Code:
define loader_used 1  
define osc 20        

led var portc.1            ;LED is connected on PortC.1
ledcnt var word

wsave var   byte $20 system
ssave var   byte bank0 system
psave var   byte bank0 system

Goto main

define INTHAND tmroverflow

asm
tmroverflow movwf	wsave
            swapf	STATUS, W
            clrf	STATUS
            movwf	ssave              ;Interrupt
            movf	PCLATH, W          ;Routine
            movwf	psave              ;with Save function
                                       
            inc          _ledcnt            ;increment the counter
            
            movf	psave, W
            movwf	PCLATH
            swapf	ssave, W
            movwf	STATUS
            swapf	wsave, F
            swapf	wsave, W
            
            bcf     intcon,2           ;Clear Interrupt Flag
            
            retfie
ENDASM

main:
   INTCON = %10100000                  ;GIE enabled, T0IE enabled
   OPTION_REG = %00000101              ;Prescaler on TMR0 rate 1:32
   Output LED
   
loop:
   led = ledcnt.7                     ;make the led follow bit 7 of ledcounter
   goto loop                           ;Wait here for interrupt
A couple of changes. If you don't see the LED blink, turn up the prescaler and/or use a slower oscillator for test. At least you should see it work.