[CodeCompletion] Remove unsound check in override completion

In override completion, we didn't use to emit 'class var' with the initial
expression. However, having initial expression does not have any bearing
on whether the declaration is overridable or not.

Author: rintaro

lib/IDE/CodeCompletion.cpp

@@ -4399,10 +4399,6 @@ class CompletionOverrideLookup : public swift::VisibleDeclConsumer {
     if (D->isFinal())
       return;
 
-    // A 'class' member with an initial value cannot be overriden either.
-    if (D->isStatic() && isa<VarDecl>(D) && cast<VarDecl>(D)->hasInitialValue())
-      return;
-
     bool hasIntroducer = hasFuncIntroducer ||
                          hasVarIntroducer ||
                          hasTypealiasIntroducer;

test/IDE/complete_override.swift

@@ -724,9 +724,10 @@ class Override26 : OverrideBase, OverrideP {
   // Same as MODIFIER24
 }
 
-// MODIFIER1: Begin completions, 9 items
+// MODIFIER1: Begin completions, 10 items
 // MODIFIER1-DAG: Decl[Constructor]/Super:            required init(p: Int) {|}; name=required init(p: Int)
 // MODIFIER1-DAG: Decl[StaticMethod]/Super:           override class func classMethod() {|}; name=classMethod()
+// MODIFIER1-DAG: Decl[StaticVar]/Super:              override class var classVar: Int; name=classVar: Int
 // MODIFIER1-DAG: Decl[StaticVar]/Super:              override class var classGetOnlyVar: Int; name=classGetOnlyVar: Int
 // MODIFIER1-DAG: Decl[InstanceMethod]/Super:         override func defaultMethod() {|}; name=defaultMethod()
 // MODIFIER1-DAG: Decl[InstanceMethod]/Super:         override func openMethod() {|}; name=openMethod()
@@ -736,7 +737,8 @@ class Override26 : OverrideBase, OverrideP {
 // MODIFIER1-DAG: Decl[AssociatedType]/Super:         typealias Assoc = {#(Type)#}; name=Assoc = Type
 // MODIFIER1: End completions
 
-// MODIFIER2: Begin completions, 5 items
+// MODIFIER2: Begin completions, 6 items
+// MODIFIER2-DAG: Decl[StaticVar]/Super:              override class var classVar: Int; name=classVar: Int
 // MODIFIER2-DAG: Decl[StaticVar]/Super:              override class var classGetOnlyVar: Int; name=classGetOnlyVar: Int
 // MODIFIER2-DAG: Decl[StaticMethod]/Super:           override class func classMethod() {|}; name=classMethod()
 // MODIFIER2-DAG: Decl[InstanceMethod]/Super:         override func defaultMethod() {|}; name=defaultMethod()
@@ -760,7 +762,8 @@ class Override26 : OverrideBase, OverrideP {
 // MODIFIER6-DAG: Decl[AssociatedType]/Super:         Assoc = {#(Type)#}; name=Assoc = Type
 // MODIFIER6: End completions
 
-// MODIFIER7: Begin completions, 7 items
+// MODIFIER7: Begin completions, 8 items
+// MODIFIER7-DAG: Decl[StaticVar]/Super:              class var classVar: Int; name=classVar: Int
 // MODIFIER7-DAG: Decl[StaticVar]/Super:              class var classGetOnlyVar: Int; name=classGetOnlyVar: Int
 // MODIFIER7-DAG: Decl[StaticMethod]/Super:           class func classMethod() {|}; name=classMethod()
 // MODIFIER7-DAG: Decl[InstanceMethod]/Super:         func defaultMethod() {|}; name=defaultMethod()
@@ -785,11 +788,13 @@ class Override26 : OverrideBase, OverrideP {
 
 // MODIFIER13-NOT: Begin completions
 
-// MODIFIER15: Begin completions, 1 items
+// MODIFIER15: Begin completions, 2 items
+// MODIFIER15-DAG: Decl[StaticVar]/Super/Erase[4]:    override var classVar: Int; name=classVar: Int
 // MODIFIER15-DAG: Decl[StaticVar]/Super/Erase[4]:    override var classGetOnlyVar: Int; name=classGetOnlyVar: Int
 // MODIFIER15: End completions
 
-// MODIFIER17: Begin completions, 1 items
+// MODIFIER17: Begin completions, 2 items
+// MODIFIER17-DAG: Decl[StaticVar]/Super:             classVar: Int; name=classVar: Int
 // MODIFIER17-DAG: Decl[StaticVar]/Super:             classGetOnlyVar: Int; name=classGetOnlyVar: Int
 // MODIFIER17: End completions
 
@@ -801,13 +806,15 @@ class Override26 : OverrideBase, OverrideP {
 // MODIFIER22: Decl[StaticMethod]/Super/Erase[5]:     override func classMethod() {|}; name=classMethod()
 // MODIFIER22: End completions
 
-// MODIFIER23: Begin completions, 2 items
+// MODIFIER23: Begin completions, 3 items
 // MODIFIER23-DAG: Decl[StaticMethod]/Super:          override func classMethod() {|}; name=classMethod()
+// MODIFIER23-DAG: Decl[StaticVar]/Super:             override var classVar: Int; name=classVar: Int
 // MODIFIER23-DAG: Decl[StaticVar]/Super:             override var classGetOnlyVar: Int; name=classGetOnlyVar: Int
 // MODIFIER23: End completions
 
-// MODIFIER24: Begin completions, 2 items
+// MODIFIER24: Begin completions, 3 items
 // MODIFIER24-DAG: Decl[StaticMethod]/Super:          func classMethod() {|}; name=classMethod()
+// MODIFIER24-DAG: Decl[StaticVar]/Super:             var classVar: Int; name=classVar: Int
 // MODIFIER24-DAG: Decl[StaticVar]/Super:             var classGetOnlyVar: Int; name=classGetOnlyVar: Int
 // MODIFIER24: End completions