Renames the assembler* files.

Renames the assembler* files to IceAssembler*. Fixes whatever breaks.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4077
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/1179563004.
diff --git a/src/IceCfg.cpp b/src/IceCfg.cpp
index 5c2f9ad..12de452 100644
--- a/src/IceCfg.cpp
+++ b/src/IceCfg.cpp
@@ -12,7 +12,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "assembler.h"
+#include "IceAssembler.h"
 #include "IceCfg.h"
 #include "IceCfgNode.h"
 #include "IceClFlags.h"