Ensure calls to getters have a source location.

include/swift/SIL/SILLocation.h

@@ -343,7 +343,7 @@ class SILLocation {
   /// Marks the location as coming from auto-generated body.
   void markAutoGenerated() { kindAndFlags.fields.autoGenerated = true; }
 
-  /// Marks the location as not bein auto-generated.
+  /// Marks the location as not being auto-generated.
   /// FIXME: This functionality is only used to work around bugs and should be
   /// removed.
   void markNonAutoGenerated() { kindAndFlags.fields.autoGenerated = false; }
@@ -364,6 +364,9 @@ class SILLocation {
   ///       and these two properties should be merged.
   bool isImplicit() const { return kindAndFlags.fields.implicit; }
 
+  /// Mark this location as not being implicit.
+  void markExplicit() { kindAndFlags.fields.implicit = false; }
+
   /// Returns false if the location should be represented in debuginfo.
   bool isHiddenFromDebugInfo() const {
     return (isAutoGenerated() || isImplicit()) && !hasASTNodeForDebugging();

lib/SILGen/SILGenApply.cpp

@@ -6635,6 +6635,11 @@ RValue SILGenFunction::emitGetAccessor(
   // Scope any further writeback just within this operation.
   FormalEvaluationScope writebackScope(*this);
 
+  // Calls to getters are implicit because the compiler inserts them on a
+  // property access, but the location is useful in backtraces so it should be
+  // preserved.
+  loc.markExplicit();
+
   Callee getter = emitSpecializedAccessorFunctionRef(
       *this, loc, get, substitutions, selfValue, isSuper, isDirectUse,
       isOnSelfParameter);

test/DebugInfo/lazy-getter.swift

@@ -0,0 +1,10 @@
+// RUN: %target-swift-frontend %s -Onone -emit-ir -g -o - -parse-as-library -module-name a | %FileCheck %s
+func use<T>(_ t : T) {}
+public func f() -> (() -> ()) {
+    lazy var i : Int = 0
+  return {
+      // CHECK: call {{.*}} @"$s1a1fyycyF1iL_Sivg"({{.*}}), !dbg ![[GETTER_LOC:[0-9]+]]
+      // CHECK: ![[GETTER_LOC]] = !DILocation(line: [[@LINE+1]], column: 11
+      use(i)
+    }
+}