... avr-g++ ... -IC:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\tiny
* Locate the Arduino Sketchbook folder. This is the folder where the Arduino IDE stores Sketches.
I have had the same problem. The ATTINY 2313 does not have a bootloader, so all you can do with it is ISP. You need to use avrdude -p t2313 -cstk500v1 -P COM18 -b115200 -D -Uflash:w:Blink.hex:i