Merge branch 'db/implicit-to-string'

# Conflicts:
#	java/compiler/impl/src/com/intellij/compiler/backwardRefs/CompilerReferenceServiceImpl.java
#	java/java-indexing-impl/src/com/intellij/compiler/CompilerReferenceService.java
#	jps/jps-builders-6/src/org/jetbrains/jps/javac/ast/JavacTreeRefScanner.java
#	jps/jps-builders/testSrc/org/jetbrains/references/ReferenceIndexTest.kt

java/java-indexing-api/src/com/intellij/psi/search/searches/ImplicitToStringSearch.java

@@ -0,0 +1,37 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.intellij.psi.search.searches;
+
+import com.intellij.psi.PsiExpression;
+import com.intellij.psi.PsiMethod;
+import com.intellij.psi.search.SearchScope;
+import com.intellij.util.Query;
+import org.jetbrains.annotations.NotNull;
+
+public class ImplicitToStringSearch extends ExtensibleQueryFactory<PsiExpression, ImplicitToStringSearch.SearchParameters> {
+  public static final ImplicitToStringSearch INSTANCE = new ImplicitToStringSearch();
+
+  public static class SearchParameters {
+    private final PsiMethod myTargetMethod;
+    @NotNull
+    private final SearchScope myScope;
+
+    public SearchParameters(@NotNull PsiMethod targetMethod, @NotNull SearchScope scope) {
+      myTargetMethod = targetMethod;
+      myScope = scope;
+    }
+
+    @NotNull
+    public PsiMethod getTargetMethod() {
+      return myTargetMethod;
+    }
+
+    @NotNull
+    public SearchScope getSearchScope() {
+      return myScope;
+    }
+  }
+
+  public static Query<PsiExpression> search(@NotNull PsiMethod targetMethod, @NotNull SearchScope scope) {
+    return INSTANCE.createUniqueResultsQuery(new SearchParameters(targetMethod, scope));
+  }
+}