qdoc: Adjust formatting of reports

Location::report() was pushed directly to stderr without decorating the
message in any way. To have unified formatting with other message types
(error, warning), prefix reports with 'qdoc: '. In addition, output the
project name, to disambiguate between similar reports in a multi-module
documentation build.

Change-Id: I7696f23d79d175c926efbf7cba3ced457d9a53df
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
(cherry picked from commit ebab8cd15995af4a72314b1a5c19ebbee5227c68)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit 18d477f43c411b428bfba823aa164d10a3e644d5)

src/qdoc/qdoc/src/qdoc/location.cpp

@@ -13,6 +13,8 @@
 #include <cstdio>
 #include <cstdlib>
 
+using namespace Qt::Literals::StringLiterals;
+
 QT_BEGIN_NAMESPACE
 
 int Location::s_tabSize;
@@ -382,6 +384,8 @@ void Location::emitMessage(MessageType type, const QString &message, const QStri
     }
     if (type != Report)
         result.prepend(toString());
+    else
+        result.prepend("qdoc: '%1': "_L1.arg(s_project));
     fprintf(stderr, "%s\n", result.toLatin1().data());
     fflush(stderr);
 }