Subzero: Render constants in dump() to be more like LLVM.

Integers are generally dumped as signed instead of unsigned values.
Integers of i1 type are dumped as 'false' and 'true'.  Floating point
values still don't match LLVM.

BUG= none
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/539743002
diff --git a/src/IceOperand.h b/src/IceOperand.h
index 73e51e5..0828396 100644
--- a/src/IceOperand.h
+++ b/src/IceOperand.h
@@ -146,6 +146,14 @@
 typedef ConstantPrimitive<float, Operand::kConstFloat> ConstantFloat;
 typedef ConstantPrimitive<double, Operand::kConstDouble> ConstantDouble;
 
+template <> inline void ConstantInteger::dump(GlobalContext *Ctx) const {
+  Ostream &Str = Ctx->getStrDump();
+  if (getType() == IceType_i1)
+    Str << (getValue() ? "true" : "false");
+  else
+    Str << static_cast<int64_t>(getValue());
+}
+
 // RelocatableTuple bundles the parameters that are used to
 // construct an ConstantRelocatable.  It is done this way so that
 // ConstantRelocatable can fit into the global constant pool