Merge pull request #1041 from chastai/add-book

Add "Compiling Techniques" by F.R.A. Hopgood

free-programming-books.md

@@ -276,6 +276,7 @@
 * [Compiler Design: Theory, Tools, and Examples, C/C++ Edition](http://elvis.rowan.edu/~bergmann/books/c_cpp/) - Seth D. Bergmann
 * [Compiler Design: Theory, Tools, and Examples, Java Edition](http://elvis.rowan.edu/~bergmann/books/java/) - Seth D. Bergmann
 * [Compiling Scala for the Java Virtual Machine](http://lampwww.epfl.ch/~schinz/thesis-final-A4.pdf) - Michel Schinz
+* [Compiling Techniques](http://www.chilton-computing.org.uk/acl/literature/books/compilingtechniques/overview.htm) - F.R.A. Hopgood, Macdonald, 1969
 * [Implementing Functional Languages: A Tutorial](http://research.microsoft.com/en-us/um/people/simonpj/Papers/pj-lester-book/) - Simon Peyton Jones, David Lester
 * [Let's Build a Compiler](http://www.stack.nl/~marcov/compiler.pdf) (PDF)
 * [Linkers and Loaders](http://www.iecc.com/linker/) - John R. Levine