SILDebugScopes: Don't ignore ConditionalClauseInitializerScope.

ConditionalClauseInitializerScope often create redundant scopes, however, they
are needed to correctly represent the scopes in an expression such as:

  if case .something(let foo), let foo = foo.

This patch changes SILGen to lower them 1:1 from ASTScopes.

rdar://110841130

Author: adrian-prantl

include/swift/AST/ASTScope.h

@@ -990,7 +990,6 @@ class ConditionalClauseInitializerScope final : public ASTScopeImpl {
   SourceRange
   getSourceRangeOfThisASTNode(bool omitAssertions = false) const override;
   std::string getClassName() const override;
-  bool ignoreInDebugInfo() const override { return true; }
 
 private:
   void expandAScopeThatDoesNotCreateANewInsertionPoint(ScopeCreator &);

test/DebugInfo/case-scope3.swift

@@ -0,0 +1,22 @@
+// RUN: %target-swift-frontend -module-name a -parse-as-library -emit-sil -g %s | %FileCheck %s
+
+enum E {
+case integerValue(Int?)
+}
+
+func getE() -> E? { return .integerValue(0) }
+
+func f() -> Int {
+    if case .integerValue(let nextValue) = getE(), let nextValue = nextValue {
+// CHECK: sil_scope [[F:[0-9]+]] { loc "{{.*}}":9:6 parent @$s1a1fSiyF
+// CHECK: sil_scope [[S0:[0-9]+]] { loc "{{.*}}":10:5 parent [[F]] }
+// CHECK: sil_scope [[S1:[0-9]+]] { loc "{{.*}}":10:44 parent [[S0]] }
+// CHECK: sil_scope [[S2:[0-9]+]] { loc "{{.*}}":10:44 parent [[S0]] }
+// CHECK: sil_scope [[S3:[0-9]+]] { loc "{{.*}}":10:68 parent [[S2]] }
+// CHECK: sil_scope [[S4:[0-9]+]] { loc "{{.*}}":10:78 parent [[S3]] }
+// CHECK: debug_value {{.*}}: $Optional<Int>, let, name "nextValue", {{.*}}:10:31, scope [[S0]]
+// CHECK: debug_value {{.*}}: $Int, let, name "nextValue", {{.*}}:10:56, scope [[S2]]
+        return nextValue
+    }
+    return 0
+}

test/DebugInfo/guard-let-scope.swift

@@ -10,12 +10,14 @@ func f(c: AnyObject??) {
   // CHECK: sil_scope [[S5:[0-9]+]] { {{.*}} parent [[S3]] }
   // CHECK: sil_scope [[S6:[0-9]+]] { loc "{{.*}}":7:3 parent [[S5]] }
   // CHECK: sil_scope [[S7:[0-9]+]] { loc "{{.*}}":7:17 parent [[S6]] }
-  // CHECK: sil_scope [[S8:[0-9]+]] { loc "{{.*}}":7:28 parent [[S7]] }
+  // CHECK: sil_scope [[S8:[0-9]+]] { loc "{{.*}}":7:17 parent [[S6]] }
+  // CHECK: sil_scope [[S9:[0-9]+]] { loc "{{.*}}":7:28 parent [[S8]] }
+  // CHECK: sil_scope [[S10:[0-9]+]] { loc "{{.*}}":7:28 parent [[S8]] }
   // CHECK: debug_value %{{.*}} : $Optional<Optional<AnyObject>>, let, name "x"{{.*}} scope [[S5]]
-  // CHECK: debug_value %{{.*}} : $Optional<AnyObject>, let, name "x", {{.*}} scope [[S7]]
+  // CHECK: debug_value %{{.*}} : $Optional<AnyObject>, let, name "x", {{.*}} scope [[S6]]
   // CHECK: debug_value %{{.*}} : $AnyObject, let, name "x", {{.*}} scope [[S8]]
     fatalError()
   }
-  // CHECK: function_ref {{.*3use.*}} scope [[S8]]
+  // CHECK: function_ref {{.*3use.*}} scope [[S10]]
   use(x)
 }

test/DebugInfo/guard-let-scope3.swift

@@ -7,13 +7,16 @@ public class S {
   private var c = [Int : C?]()
   public func f(_ i: Int) throws  -> C {
     guard let x = c[i], let x else {
-      // CHECK: sil_scope [[P:[0-9]+]] { loc "{{.*}}":[[@LINE-1]]:5
-      // CHECK: sil_scope [[X1:[0-9]+]] { loc "{{.*}}":[[@LINE-2]]:19 parent [[P]]
-      // CHECK: sil_scope [[X2:[0-9]+]] { loc "{{.*}}":[[@LINE-3]]:29 parent [[X1]]
-      // CHECK: sil_scope [[GUARD:[0-9]+]] { loc "{{.*}}":[[@LINE-4]]:36 parent [[P]]
-      // CHECK: debug_value {{.*}} : $Optional<C>, let, name "x", {{.*}}, scope [[X1]]
+      // CHECK: sil_scope [[P:[0-9]+]] { loc "{{.*}}":9:5
+      // CHECK: sil_scope [[X1_:[0-9]+]] { loc "{{.*}}":9:19 parent [[P]]
+      // CHECK: sil_scope [[X1:[0-9]+]] { loc "{{.*}}":9:19 parent [[P]]
+      // CHECK: sil_scope [[X2:[0-9]+]] { loc "{{.*}}":9:29 parent [[X1]]
+      // CHECK: sil_scope [[X2_:[0-9]+]] { loc "{{.*}}":9:29 parent [[X1]]
+      // CHECK: sil_scope [[GUARD:[0-9]+]] { loc "{{.*}}":9:36 parent [[P]]
+      // CHECK: debug_value {{.*}} : $Optional<C>, let, name "x", {{.*}}, scope [[P]]
       // CHECK: debug_value {{.*}} : $C, let, name "x", {{.*}}, scope [[X2]]
-      // CHECK-NEXT:  scope [[X2]]
+      // FIXME: This source location & scope are a little wild.
+      // CHECK-NEXT: strong_retain{{.*}}:[[@LINE+4]]:12, scope [[X2_]]
       throw MyError()
       // CHECK: function_ref {{.*}}MyError{{.*}}:[[@LINE-1]]:13, scope [[GUARD]]
     }

test/DebugInfo/if-let-scope.swift

@@ -1,10 +1,12 @@
 // RUN: %target-swift-frontend -g -emit-sil %s -parse-as-library -module-name a | %FileCheck %s
 func use<T>(_ t: T) {}
 public func f(value: String?) {
-  // CHECK: sil_scope [[S0:[0-9]+]] { loc "{{.*}}":[[@LINE-1]]:13
+  // CHECK: sil_scope [[S0:[0-9]+]] { loc "{{.*}}":3:13
   if let value, let value = Int(value) {
-    // CHECK: sil_scope [[S1:[0-9]+]] { loc "{{.*}}":[[@LINE-1]]:10
-    // CHECK: sil_scope [[S2:[0-9]+]] { loc "{{.*}}":[[@LINE-2]]:29 parent [[S1]] }
+    // CHECK: sil_scope [[S1:[0-9]+]] { loc "{{.*}}":5:10
+    // CHECK: sil_scope [[S2:[0-9]+]] { loc "{{.*}}":5:10
+    // CHECK: sil_scope [[S3:[0-9]+]] { loc "{{.*}}":5:29 parent [[S2]] }
+    // CHECK: sil_scope [[S4:[0-9]+]] { loc "{{.*}}":5:29 parent [[S2]] }
     // CHECK: debug_value {{.*}} : $Optional<String>, let, name "value", {{.*}}, scope [[S0]]
     // CHECK: debug_value {{.*}} : $String, let, name "value", {{.*}}, scope [[S1]]
     // CHECK: debug_value {{.*}} : $Int, let, name "value", {{.*}}, scope [[S2]]