C++: Rename Block -> BlockStmt

cpp/ql/examples/snippets/emptyblock.ql

@@ -9,6 +9,6 @@
 
 import cpp
 
-from Block blk
+from BlockStmt blk
 where blk.getNumStmt() = 0
 select blk

cpp/ql/examples/snippets/emptythen.ql

@@ -13,5 +13,5 @@
 import cpp
 
 from IfStmt i
-where i.getThen().(Block).getNumStmt() = 0
+where i.getThen().(BlockStmt).getNumStmt() = 0
 select i

cpp/ql/examples/snippets/singletonblock.ql

@@ -8,6 +8,6 @@
 
 import cpp
 
-from Block b
+from BlockStmt b
 where b.getNumStmt() = 1
 select b