fix: Emit refs for templated free functions

indexer/ClangAstMacros.h

@@ -7,6 +7,7 @@
   F(Enum)                              \
   F(Field)                             \
   F(Function)                          \
+  F(FunctionTemplate)                  \
   F(Namespace)                         \
   F(NonTypeTemplateParm)               \
   F(Record)                            \

indexer/Indexer.cc

@@ -474,6 +474,11 @@ void TuIndexer::saveFunctionDecl(const clang::FunctionDecl &functionDecl) {
   }
 }
 
+void TuIndexer::saveFunctionTemplateDecl(const clang::FunctionTemplateDecl &) {
+  // Handled by saveFunctionDecl.
+  return;
+}
+
 void TuIndexer::saveNamespaceDecl(const clang::NamespaceDecl &namespaceDecl) {
   auto optSymbol = this->symbolFormatter.getNamespaceSymbol(namespaceDecl);
   if (!optSymbol.has_value()) {

indexer/SymbolFormatter.cc

@@ -447,6 +447,11 @@ SymbolFormatter::getFunctionSymbol(const clang::FunctionDecl &functionDecl) {
       });
 }
 
+std::optional<std::string_view> SymbolFormatter::getFunctionTemplateSymbol(
+    const clang::FunctionTemplateDecl &functionTemplateDecl) {
+  return this->getFunctionSymbol(*functionTemplateDecl.getTemplatedDecl());
+}
+
 std::optional<std::string_view>
 SymbolFormatter::getFieldSymbol(const clang::FieldDecl &fieldDecl) {
   if (fieldDecl.getDeclName().isEmpty()) {

test/index/functions/ctors_dtors.snapshot.cc

@@ -88,11 +88,13 @@
     C c3{move(c1)};
 //  ^ reference [..] C#
 //    ^^ definition local 10
+//       ^^^^ reference [..] move(721d19cf58c53974).
 //            ^^ reference local 7
     D d3{move(d1)};
 //  ^ reference [..] D#
 //    ^^ definition local 11
 //    ^^ reference [..] D#D(ece7426db7e2c886).
+//       ^^^^ reference [..] move(721d19cf58c53974).
 //            ^^ reference local 8
 
     C c4 = {};
@@ -130,10 +132,12 @@
     C c10 = move(c1);
 //  ^ reference [..] C#
 //    ^^^ definition local 20
+//          ^^^^ reference [..] move(721d19cf58c53974).
 //               ^^ reference local 7
     D d10 = move(d1);
 //  ^ reference [..] D#
 //    ^^^ definition local 21
 //          ^^^^ reference [..] D#D(ece7426db7e2c886).
+//          ^^^^ reference [..] move(721d19cf58c53974).
 //               ^^ reference local 8
   }

test/index/functions/templates.snapshot.cc

@@ -84,7 +84,11 @@
 //      ^^ reference [..] T0#g0(b07662a27bd562f9).
 
     h0<int>(0);
+//  ^^ reference [..] h0(9b289cee16747614).
     h0<void *>(0);
+//  ^^ reference [..] h0(9b289cee16747614).
     h1<int>(0);
+//  ^^ reference [..] h1(9b289cee16747614).
     h1<char>(0);
+//  ^^ reference [..] h1(9b289cee16747614).
   }