Debugger: Handle failing inferior calls more gracefully

At least for GDB on Windows that's a rather typical situation due to
GDB's "Internal error: pc in read in psymtab, but not in symtab"

Task-number: QTCREATORBUG-11164

Change-Id: If79d586b59e2c1ee37558e8a811091fefc69ac2d
Reviewed-by: Christian Stenger <christian.stenger@digia.com>

share/qtcreator/debugger/dumper.py

@@ -500,6 +500,18 @@ class DumperBase:
             self.putType(type)
             self.putNumChild(0)
 
+    def putCallItem(self, name, value, func, *args):
+        try:
+            result = self.callHelper(value, func, args)
+            with SubItem(self, name):
+                self.putItem(result)
+        except:
+            with SubItem(self, name):
+                self.putValue("<not callable>")
+                self.putNumChild(0)
+
+    def call(self, value, func, *args):
+        return self.callHelper(value, func, args)
 
     def putMapName(self, value, index = -1):
         ns = self.qtNamespace()