[clangd][Hover] Change arrow in return type back to →

[kadircet]

Summary

Currently 🡺 is used in hover response to represent return types, but it
is not widely available. Changing this back to original to support more clients.

[merge_guards_bot]

Unit tests: fail. 62133 tests passed, 5 failed and 807 were skipped.

failed: libc++.std/language_support/cmp/cmp_partialord/partialord.pass.cpp
failed: libc++.std/language_support/cmp/cmp_strongeq/cmp.strongeq.pass.cpp
failed: libc++.std/language_support/cmp/cmp_strongord/strongord.pass.cpp
failed: libc++.std/language_support/cmp/cmp_weakeq/cmp.weakeq.pass.cpp
failed: libc++.std/language_support/cmp/cmp_weakord/weakord.pass.cpp

clang-tidy: pass.

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

clang-tools-extra/clangd/Hover.cpp

markup::Document HoverInfo::present() const {
   Header.appendCode(Name);
 
   // Put a linebreak after header to increase readability.
   Output.addRuler();
   // Print Types on their own lines to reduce chances of getting line-wrapped by
   // editor, as they might be long.
   if (ReturnType) {
     // For functions we display signature in a list form, e.g.:
-    // 🡺 `x`
+    // → `x`
     // Parameters:
     // - `bool param1`
     // - `int param2 = 5`
-    Output.addParagraph().appendText("🡺").appendCode(*ReturnType);
+    Output.addParagraph().appendText("→").appendCode(*ReturnType);
     if (Parameters && !Parameters->empty()) {
       Output.addParagraph().appendText("Parameters:");
       markup::BulletList &L = Output.addBulletList();
       for (const auto &Param : *Parameters) {
         std::string Buffer;
         llvm::raw_string_ostream OS(Buffer);
         OS << Param;
         L.addItem().addParagraph().appendCode(std::move(OS.str()));

clang-tools-extra/clangd/test/hover.test

 # RUN: clangd -lit-test < %s | FileCheck %s
 {"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":123,"rootPath":"clangd","capabilities":{},"trace":"off"}}
 ---
 {"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"test:///main.cpp","languageId":"cpp","version":1,"text":"void foo(); int main() { foo(); }\n"}}}
 ---
 {"jsonrpc":"2.0","id":1,"method":"textDocument/hover","params":{"textDocument":{"uri":"test:///main.cpp"},"position":{"line":0,"character":27}}}
 #      CHECK:  "id": 1,
 # CHECK-NEXT:  "jsonrpc": "2.0",
 # CHECK-NEXT:  "result": {
 # CHECK-NEXT:    "contents": {
 # CHECK-NEXT:      "kind": "plaintext",
-# CHECK-NEXT:      "value": "function foo\n\n🡺 void\n\nvoid foo()"
+# CHECK-NEXT:      "value": "function foo\n\n→ void\n\nvoid foo()"
 # CHECK-NEXT:    },
 # CHECK-NEXT:    "range": {
 # CHECK-NEXT:      "end": {
 # CHECK-NEXT:        "character": 28,
 # CHECK-NEXT:        "line": 0
 # CHECK-NEXT:      },
 # CHECK-NEXT:      "start": {
 # CHECK-NEXT:        "character": 25,

clang-tools-extra/clangd/unittests/HoverTests.cpp

template <typename T, typename C = bool> class Foo {})",
             HI.Parameters->push_back(P);
             P.Default = "default";
             HI.Parameters->push_back(P);
             HI.NamespaceScope = "ns::";
             HI.Definition = "ret_type foo(params) {}";
           },
           R"(function foo
 
-🡺 ret_type
+→ ret_type
 Parameters:
 - 
 - type
 - type foo
 - type foo = default
 
 // In namespace ns
 ret_type foo(params) {})",