Fixed uninitialized memory in QMetaObjectBuilder::fromRelocatableData

static_metacall was never set on the metaobject written by
QMetaObjectBuilder::fromRelocatableData, sometimes causing a crash.  It
should be initialized to 0.

Change-Id: I79373d895e131f0cc2ff1af6d2177a0c1a282be7
Reviewed-by: Toby Tomkins <toby.tomkins@nokia.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

src/corelib/kernel/qmetaobjectbuilder.cpp

@@ -1536,6 +1536,7 @@ void QMetaObjectBuilder::fromRelocatableData(QMetaObject *output,
     output->d.data = reinterpret_cast<const uint *>(buf + dataOffset);
     output->d.extradata = 0;
     output->d.relatedMetaObjects = 0;
+    output->d.static_metacall = 0;
 }
 
 /*!

tests/auto/corelib/kernel/qmetaobjectbuilder/tst_qmetaobjectbuilder.cpp

@@ -1097,6 +1097,11 @@ void tst_QMetaObjectBuilder::relocatableData()
     QMetaObject *meta = builder.toMetaObject();
 
     QVERIFY(sameMetaObject(meta, &meta2));
+
+    QVERIFY(!meta2.d.extradata);
+    QVERIFY(!meta2.d.relatedMetaObjects);
+    QVERIFY(!meta2.d.static_metacall);
+
     free(meta);
 }