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

src/IceTargetLoweringX8632.cpp

diff --git a/src/IceTargetLoweringX8632.cpp b/src/IceTargetLoweringX8632.cpp
index 55a0bfc..4570d9f 100644
--- a/src/IceTargetLoweringX8632.cpp
+++ b/src/IceTargetLoweringX8632.cpp
@@ -229,7 +229,7 @@
 
 template <typename T>
 void TargetDataX8632::emitConstantPool(GlobalContext *Ctx) {
-  if (!ALLOW_DUMP)
+  if (!BuildDefs::dump())
     return;
   Ostream &Str = Ctx->getStrEmit();
   Type Ty = T::Ty;