Add some unit tests for Linux WriteSymbolFile

This patch adds synth_elf::{StringTable,SymbolTable,ELF} classes to
produce in-memory ELF files to properly test the Linux symbol dumping
code. It also uses those classes to add some basic tests for
the WriteSymbolFile function.

R=jimb at http://breakpad.appspot.com/277001/show

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@794 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/common/dwarf_cu_to_module.cc

@@ -40,6 +40,7 @@
 
 #include <assert.h>
 #include <inttypes.h>
+#include <stdio.h>
 
 #include <algorithm>
 #include <set>