Rust: fix Path.toString and address some review comments

Author: Paolo Tranquilli

rust/ql/.generated.list

@@ -104,7 +104,9 @@ module Impl {
       )
     }
 
-    override string toString() { result = concat(int i | | this.toStringPart(i), " " order by i) }
+    override string toString() {
+      result = strictconcat(int i | | this.toStringPart(i), " " order by i)
+    }
 
     private string toStringPart(int index) {
       index = 0 and result = "break"

rust/ql/.gitattributes

@@ -20,7 +20,7 @@ module Impl {
    */
   class CastExpr extends Generated::CastExpr {
     override string toString() {
-      result = this.getExpr().toAbbreviatedString() + " as " + this.getTy().toString()
+      result = this.getExpr().toAbbreviatedString() + " as " + this.getTy().toAbbreviatedString()
     }
   }
 }

rust/ql/lib/codeql/rust/elements/Path.qll

@@ -49,12 +49,14 @@ module Impl {
    * ```
    */
   class ContinueExpr extends Generated::ContinueExpr {
-    override string toString() { result = concat(int i | | this.toStringPart(i), " " order by i) }
+    override string toString() {
+      result = strictconcat(int i | | this.toStringPart(i), " " order by i)
+    }
 
     private string toStringPart(int index) {
       index = 0 and result = "continue"
       or
-      index = 1 and result = this.getLifetime().toString()
+      index = 1 and result = this.getLifetime().getText()
     }
 
     /**

rust/ql/lib/codeql/rust/elements/PathSegment.qll

@@ -19,6 +19,6 @@ module Impl {
    * ```
    */
   class Enum extends Generated::Enum {
-    override string toString() { result = "enum " + this.getName().toString() }
+    override string toString() { result = "enum " + this.getName().getText() }
   }
 }

rust/ql/lib/codeql/rust/elements/internal/BreakExprImpl.qll

@@ -22,7 +22,7 @@ module Impl {
     override string toString() {
       exists(string abbr, string name |
         abbr = this.getExpr().toAbbreviatedString() and
-        name = this.getNameRef().toString() and
+        name = this.getNameRef().getText() and
         if abbr = "..." then result = "... ." + name else result = abbr + "." + name
       )
     }

rust/ql/lib/codeql/rust/elements/internal/CastExprImpl.qll

@@ -22,11 +22,11 @@ module Impl {
     override string toString() {
       exists(string trait |
         (
-          trait = this.getTrait().toString() + " for "
+          trait = this.getTrait().toAbbreviatedString() + " for "
           or
           not this.hasTrait() and trait = ""
         ) and
-        result = "impl " + trait + this.getSelfTy().toString() + " { ... }"
+        result = "impl " + trait + this.getSelfTy().toAbbreviatedString() + " { ... }"
       )
     }
   }