[turbofan] Run representation selection without the Typer decorator.

src/compiler/pipeline.cc

Index: src/compiler/pipeline.cc
diff --git a/src/compiler/pipeline.cc b/src/compiler/pipeline.cc
index d5920009115d34a8ec9220b49868b75897e378ac..73d484ba197d78b1507d65e7109226b0420f3d0d 100644
--- a/src/compiler/pipeline.cc
+++ b/src/compiler/pipeline.cc
@@ -1444,12 +1444,14 @@ bool PipelineImpl::CreateGraph() {
       Run<EscapeAnalysisPhase>();
       RunPrintAndVerify("Escape Analysed");
     }
-
-    // Select representations.
-    Run<RepresentationSelectionPhase>();
-    RunPrintAndVerify("Representations selected", true);
   }
 
+  // Select representations. This has to run w/o the Typer decorator, because
+  // we cannot compute meaningful types anyways, and the computed types might
+  // even conflict with the representation/truncation logic.
+  Run<RepresentationSelectionPhase>();
+  RunPrintAndVerify("Representations selected", true);
+
 #ifdef DEBUG
   // From now on it is invalid to look at types on the nodes, because:
   //