Scope: Remove hides(..) and related predicates

There are no more consumers of hides(..).

In addition, it doesn't make sense conceptually to look for
variables in the same scope with the same name, as scopes will
prohibit using the same name in the same scope. Reviewing real
world cases where this occurs, they all seem to be extractor
oddities (multiple copies of parameters for the same function etc.)
which provides further evidence that this mode is not required.

Author: lcartey

cpp/common/src/codingstandards/cpp/Scope.qll

@@ -160,15 +160,6 @@ predicate inSameTranslationUnit(File f1, File f2) {
   )
 }
 
-/**
- * Gets a user variable which occurs in the "potential scope" of variable `v`.
- */
-cached
-UserVariable getPotentialScopeOfVariable(UserVariable v) {
-  result = getPotentialScopeOfVariable_candidate(v) and
-  inSameTranslationUnit(v.getFile(), result.getFile())
-}
-
 /**
  * Gets a user variable which occurs in the "outer scope" of variable `v`.
  */
@@ -203,15 +194,6 @@ class TranslationUnit extends SourceFile {
   }
 }
 
-/** Holds if `v2` may hide `v1`. */
-private predicate hides_candidate(UserVariable v1, UserVariable v2) {
-  not v1 = v2 and
-  v2 = getPotentialScopeOfVariable(v1) and
-  v1.getName() = v2.getName() and
-  // Member variables cannot hide other variables nor be hidden because the can be referenced through their qualified name.
-  not (v1.isMember() or v2.isMember())
-}
-
 /** Holds if `v2` may hide `v1`. */
 private predicate hides_candidateStrict(UserVariable v1, UserVariable v2) {
   not v1 = v2 and
@@ -256,16 +238,6 @@ private Stmt getEnclosingStmt(LocalScopeVariable v) {
   )
 }
 
-/** Holds if `v2` hides `v1`. */
-predicate hides(UserVariable v1, UserVariable v2) {
-  hides_candidate(v1, v2) and
-  // Confirm that there's no closer candidate variable which `v2` hides
-  not exists(UserVariable mid |
-    hides_candidate(v1, mid) and
-    hides_candidate(mid, v2)
-  )
-}
-
 /** Holds if `v2` strictly (`v2` is in an inner scope compared to `v1`) hides `v1`. */
 predicate hidesStrict(UserVariable v1, UserVariable v2) {
   hides_candidateStrict(v1, v2) and