[clangd] Handle the missing call expr in targetDecl.

[merge_guards_bot]

Build result: pass - 60325 tests passed, 0 failed and 732 were skipped.

Log files: console-log.txt, CMakeCache.txt

clang-tools-extra/clangd/FindTarget.cpp

void add(const Stmt *S, RelSet Flags) {
     if (!S)
       return;
     debug(*S, Flags);
     struct Visitor : public ConstStmtVisitor<Visitor> {
       TargetFinder &Outer;
       RelSet Flags;
       Visitor(TargetFinder &Outer, RelSet Flags) : Outer(Outer), Flags(Flags) {}
 
+      void VisitCallExpr(const CallExpr *CE) {
+        Outer.add(CE->getCalleeDecl(), Flags);
+      }
       void VisitDeclRefExpr(const DeclRefExpr *DRE) {
         const Decl *D = DRE->getDecl();
         // UsingShadowDecl allows us to record the UsingDecl.
         // getFoundDecl() returns the wrong thing in other cases (templates).
         if (auto *USD = llvm::dyn_cast<UsingShadowDecl>(DRE->getFoundDecl()))
           D = USD;
         Outer.add(D, Flags);
       }

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

TEST_F(TargetDeclTest, Exprs) {
   )cpp";
   EXPECT_DECLS("DeclRefExpr", "int f()");
 
   Code = R"cpp(
     struct S { S operator+(S) const; };
     auto X = S() [[+]] S();
   )cpp";
   EXPECT_DECLS("DeclRefExpr", "S operator+(S) const");
+
+  Code = R"cpp(
+    int foo();
+    int s = foo[[()]];
+  )cpp";
+  EXPECT_DECLS("CallExpr", "int foo()");
+
+  Code = R"cpp(
+    struct X {
+    void operator()(int n);
+    };
+    void test() {
+      X x;
+      x[[(123)]];
+    }
+  )cpp";
+  EXPECT_DECLS("CXXOperatorCallExpr", "void operator()(int n)");
 }
 
 TEST_F(TargetDeclTest, UsingDecl) {
   Code = R"cpp(
     namespace foo {
       int f(int);
       int f(char);
     }