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>

src/plugins/clangtools/clangtoolsdiagnostic.cpp

@@ -33,6 +33,15 @@ bool ExplainingStep::isValid() const
     return location.isValid() && !ranges.isEmpty() && !message.isEmpty();
 }
 
+bool operator==(const ExplainingStep &lhs, const ExplainingStep &rhs)
+{
+    return lhs.message == rhs.message
+        && lhs.location == rhs.location
+        && lhs.ranges == rhs.ranges
+        && lhs.isFixIt == rhs.isFixIt
+        ;
+}
+
 bool Diagnostic::isValid() const
 {
     return !description.isEmpty();
@@ -46,5 +55,16 @@ quint32 qHash(const Diagnostic &diagnostic)
          ^ diagnostic.location.column;
 }
 
+bool operator==(const Diagnostic &lhs, const Diagnostic &rhs)
+{
+    return lhs.description == rhs.description
+        && lhs.category == rhs.category
+        && lhs.type == rhs.type
+        && lhs.location == rhs.location
+        && lhs.explainingSteps == rhs.explainingSteps
+        && lhs.hasFixits == rhs.hasFixits
+        ;
+}
+
 } // namespace Internal
 } // namespace ClangTools