systemc: Get rid of implementations for some disabled sc_vector methods.

These don't need to exist, and the specifics of their stub
implementations were upsetting clang.

Change-Id: Ib38a39c5cfbc2e1647cfb6ed14c660e10df2b1c3
Reviewed-on: https://gem5-review.googlesource.com/c/13878
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/systemc/ext/utils/sc_vector.hh

@@ -586,8 +586,8 @@ class sc_vector : public sc_vector_base
 
   private:
     // Disabled
-    sc_vector(const sc_vector &) : sc_vector_base() {}
-    sc_vector &operator = (const sc_vector &) { return *this; }
+    sc_vector(const sc_vector &);
+    sc_vector &operator = (const sc_vector &);
 
     void
     clear()