Makefile for interpreter in C
You should investigate whether GNU Make (or whichever Make implementation your users are supposed to use) has a special variable for all dependencies of the current rule, so that you don't need to list the source files twice.
The command line for gcc is missing the -Wall -Wextra -O2 options to catch common mistakes and to make the program run faster.
If you want the Makefile to be portable to systems other than GNU Linux on x86_64, you should switch to GNU autoconf, but that's a lot of work. If your project is just a toy project, it's fine as it is.