Subzero: Reduce the amount of #ifdef'd code.

Try to make most #ifdef'd code be compiled under all configurations,
to catch code rot earlier.  When #ifdef code is required, try to use
it only to guard trivial code like "return;".

BUG= none
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/1197863003
diff --git a/src/IceTypes.cpp b/src/IceTypes.cpp
index 793e175..f12f330 100644
--- a/src/IceTypes.cpp
+++ b/src/IceTypes.cpp
@@ -260,7 +260,7 @@
 }
 
 void FuncSigType::dump(Ostream &Stream) const {
-  if (!ALLOW_DUMP)
+  if (!BuildDefs::dump())
     return;
   Stream << ReturnType << " (";
   bool IsFirst = true;