Merge pull request #40 from parvizp/compile_mac_10.9.2

Builds on Mac 10.9.2 with LLVM 3.5.

frontends/ast/ast.cc

@@ -32,7 +32,12 @@
 
 #include <sstream>
 #include <stdarg.h>
+
+#if defined(__APPLE__)
+#include <cmath>
+#else
 #include <math.h>
+#endif
 
 YOSYS_NAMESPACE_BEGIN
 

kernel/yosys.cc

@@ -33,6 +33,9 @@
 #  include <io.h>
 #elif defined(__APPLE__)
 #  include <mach-o/dyld.h>
+#  include <unistd.h>
+#  include <dirent.h>
+#  include <sys/stat.h>
 #else
 #  include <unistd.h>
 #  include <dirent.h>