[optimizing compiler] Add CMP{L,G}_{FLOAT,DOUBLE}

Adds:
- float comparison for arm, x86, x86_64 backends.
- ucomis{s,d} assembly to x86 and x86_64.
- vmstat assebmly for thumb2
- new assembly tests

Change-Id: Ie3e19d0c08b3b875cd0a4be4ee4e9c8a4a076290
diff --git a/compiler/utils/x86/assembler_x86.h b/compiler/utils/x86/assembler_x86.h
index 6ea66a5..a630ccd 100644
--- a/compiler/utils/x86/assembler_x86.h
+++ b/compiler/utils/x86/assembler_x86.h
@@ -301,6 +301,8 @@
 
   void comiss(XmmRegister a, XmmRegister b);
   void comisd(XmmRegister a, XmmRegister b);
+  void ucomiss(XmmRegister a, XmmRegister b);
+  void ucomisd(XmmRegister a, XmmRegister b);
 
   void sqrtsd(XmmRegister dst, XmmRegister src);
   void sqrtss(XmmRegister dst, XmmRegister src);