C++: Mark deprecated overrides as deprecated

The QL compiler is about to be changed to emit a warning when overriding a deprecated predicate. This PR marks the existing overrides of deprecated predicates as `deprecated` themselves, which avoids the warning.

The `Print.qll` models seem to preserve the `isWideCharDefault()` predicate for backwards compatibility, so we can't remove them and must continue overriding them.

The `XML.qll` override is necessary because both superclasses declare the `getName()` predicate. One is `deprecated`, and the other is `abstract`, so we have to have an override.

Author: Dave Bartolomeo

cpp/ql/src/semmle/code/cpp/XML.qll

@@ -119,7 +119,7 @@ class XMLFile extends XMLParent, File {
   override string toString() { result = XMLParent.super.toString() }
 
   /** Gets the name of this XML file. */
-  override string getName() { result = File.super.getAbsolutePath() }
+  deprecated override string getName() { result = File.super.getAbsolutePath() }
 
   /**
    * DEPRECATED: Use `getAbsolutePath()` instead.

cpp/ql/src/semmle/code/cpp/models/implementations/Printf.qll

@@ -19,7 +19,7 @@ class Printf extends FormattingFunction, AliasFunction {
 
   override int getFormatParameterIndex() { result = 0 }
 
-  override predicate isWideCharDefault() {
+  deprecated override predicate isWideCharDefault() {
     hasGlobalOrStdName("wprintf") or
     hasGlobalName("wprintf_s")
   }
@@ -47,7 +47,7 @@ class Fprintf extends FormattingFunction {
 
   override int getFormatParameterIndex() { result = 1 }
 
-  override predicate isWideCharDefault() { hasGlobalOrStdName("fwprintf") }
+  deprecated override predicate isWideCharDefault() { hasGlobalOrStdName("fwprintf") }
 
   override int getOutputParameterIndex() { result = 0 }
 }
@@ -70,7 +70,7 @@ class Sprintf extends FormattingFunction {
     not exists(getDefinition().getFile().getRelativePath())
   }
 
-  override predicate isWideCharDefault() {
+  deprecated override predicate isWideCharDefault() {
     getParameter(getFormatParameterIndex())
         .getType()
         .getUnspecifiedType()
@@ -136,7 +136,7 @@ class Snprintf extends FormattingFunction {
     else result = getFirstFormatArgumentIndex() - 1
   }
 
-  override predicate isWideCharDefault() {
+  deprecated override predicate isWideCharDefault() {
     getParameter(getFormatParameterIndex())
         .getType()
         .getUnspecifiedType()
@@ -201,7 +201,7 @@ class StringCchPrintf extends FormattingFunction {
     if getName().matches("%Ex") then result = 5 else result = 2
   }
 
-  override predicate isWideCharDefault() {
+  deprecated override predicate isWideCharDefault() {
     getParameter(getFormatParameterIndex())
         .getType()
         .getUnspecifiedType()