[tests] Update test oracles

tests/specs/oracle/assigns.res.oracle

@@ -4,7 +4,7 @@ Now output intermediate result
 [eva] Analyzing a complete application starting at main
 [eva:initial-state] Values of globals at initialization
   
-[kernel:annot:missing-spec] assigns.cc:14: Warning: 
+[kernel:annot:missing-spec] assigns.cc:8: Warning: 
   Neither code nor explicit assigns for function swap,
    generating default clauses from the specification. See -generated-spec-* options for more info
 [eva] using specification for function swap

tests/stl/oracle/stl_unique_ptr.res.oracle

@@ -254,7 +254,7 @@ Now output intermediate result
   _frama_c_rtti_name_info.name ∈ {{ "ClassTemplate" }}
                          {.base_classes; .number_of_base_classes; .pvmt} ∈
                          {0}
-[kernel:annot:missing-spec] stl_unique_ptr.cpp:9: Warning: 
+[kernel:annot:missing-spec] <builtin>:0: Warning: 
   Neither code nor specification for function malloc,
    generating default assigns. See -generated-spec-* options for more info
 [eva] using specification for function malloc

tests/val_analysis/oracle/union.res.oracle

 [kernel] Parsing union.cc (external front-end)
 Now output intermediate result
 [kernel] Warning: Assuming declared function Frama_C_memcpy can't throw any exception
-[kernel:annot:missing-spec] union.cc:8: Warning: 
+[kernel:annot:missing-spec] <builtin>:0: Warning: 
   Neither code nor specification for function Frama_C_memcpy,
    generating default assigns. See -generated-spec-* options for more info
 [eva] Analyzing a complete application starting at main

tests/val_analysis/oracle/union_struct.res.oracle

 [kernel] Parsing union_struct.cc (external front-end)
 Now output intermediate result
 [kernel] Warning: Assuming declared function Frama_C_memcpy can't throw any exception
-[kernel:annot:missing-spec] union_struct.cc:17: Warning: 
+[kernel:annot:missing-spec] <builtin>:0: Warning: 
   Neither code nor specification for function Frama_C_memcpy,
    generating default assigns. See -generated-spec-* options for more info
 [eva] Analyzing a complete application starting at main