libsysprof-analyze: add basic symbolize API

This isn't what it will look like in final form, just get the minimum
there for us to use it with the bundled decoder (copied from libsysprof
with adaptations).

src/libsysprof-analyze/sysprof-symbolizer.c

@@ -89,3 +89,12 @@ _sysprof_symbolizer_prepare_finish (SysprofSymbolizer  *self,
 
   return SYSPROF_SYMBOLIZER_GET_CLASS (self)->prepare_finish (self, result, error);
 }
+
+SysprofSymbol *
+_sysprof_symbolizer_symbolize (SysprofSymbolizer *self,
+                               gint64             time,
+                               int                pid,
+                               SysprofAddress     address)
+{
+  return SYSPROF_SYMBOLIZER_GET_CLASS (self)->symbolize (self, time, pid, address);
+}