ClangTools: Support loading exported diagnostics

Add a new toolbar button to load diagnostics exported with

   $ clang-tidy -export-fixes=/path/to/file
   $ clazy-standalone -export-fixes=/path/to/file (master version)

Change-Id: I8316fe0706a18222e68220ef4fbfdc7ae8d09804
Reviewed-by: David Schulz <david.schulz@qt.io>

tests/unit/unittest/gtest-creator-printing.cpp

@@ -64,6 +64,12 @@
 #include <tooltipinfo.h>
 #include <usedmacro.h>
 #include <utils/link.h>
+#include <cpptools/usages.h>
+#include <projectexplorer/projectmacro.h>
+#include <projectexplorer/headerpath.h>
+#include <coreplugin/find/searchresultitem.h>
+#include <coreplugin/locator/ilocatorfilter.h>
+#include <clangtools/clangtoolsdiagnostic.h>
 
 namespace {
 ClangBackEnd::FilePathCaching *filePathCache = nullptr;
@@ -1303,6 +1309,38 @@ std::ostream &operator<<(std::ostream &out, const Usage &usage)
 }
 } // namespace CppTools
 
+namespace Debugger {
+std::ostream &operator<<(std::ostream &out, const DiagnosticLocation &loc)
+{
+    return out << "(" << loc.filePath << ", " << loc.line << ", " << loc.column << ")";
+}
+} // namespace Debugger
+
+namespace ClangTools {
+namespace Internal {
+std::ostream &operator<<(std::ostream &out, const ExplainingStep &step)
+{
+    return out << "("
+               << step.message << ", "
+               << step.location << ", "
+               << step.ranges << ", "
+               << step.isFixIt
+               << ")";
+}
+
+std::ostream &operator<<(std::ostream &out, const Diagnostic &diag) {
+    return out << "("
+               << diag.description << ", "
+               << diag.category << ", "
+               << diag.type << ", "
+               << diag.location << ", "
+               << diag.explainingSteps << ", "
+               << diag.hasFixits
+               << ")";
+}
+} // namespace Internal
+} // namespace ClangTools
+
 void setFilePathCache(ClangBackEnd::FilePathCaching *cache)
 {
     filePathCache = cache;