Add more ignorable build artifacts.

.gitignore

@@ -2,11 +2,25 @@
 *.x86
 *.llvm
 *.out
+*.cmx
+*.dll
 *.exe
 *.orig
 *.cmo
 *.cmi
 *.d
 *.o
+*.aux
+*.cp
+*.fn
+*.ky
+*.log
+*.pdf
+*.html
+*.pg
+*.toc
+*.tp
+*.vr
 .hg/
 .hgignore
+lexer.ml