[turbofan] Drop broken StaticParameterTraits.

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index a3918b02f9087f893328bde4b74c7eb92f82dca5..5152fdc18291f7deb592ca85bde186d476139341 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -959,14 +959,6 @@ class ExternalReference BASE_EMBEDDED {
 
   static ExternalReference stress_deopt_count(Isolate* isolate);
 
-  bool operator==(const ExternalReference& other) const {
-    return address_ == other.address_;
-  }
-
-  bool operator!=(const ExternalReference& other) const {
-    return !(*this == other);
-  }
-
  private:
   explicit ExternalReference(void* address)
       : address_(address) {}
@@ -987,6 +979,13 @@ class ExternalReference BASE_EMBEDDED {
   void* address_;
 };
 
+bool operator==(ExternalReference, ExternalReference);
+bool operator!=(ExternalReference, ExternalReference);
+
+size_t hash_value(ExternalReference);
+
+std::ostream& operator<<(std::ostream&, ExternalReference);
+
 
 // -----------------------------------------------------------------------------
 // Position recording support