mark infinite while loops as terminators when looking for unreachable code

Cython/Compiler/ParseTreeTransforms.py

@@ -2162,6 +2162,12 @@ class RemoveUnreachableCode(CythonTransform):
                 node.is_terminator = True
         return node
 
+    def visit_WhileStatNode(self, node):
+        self.visitchildren(node)
+        if not node.condition:
+            node.is_terminator = True
+        return node
+
     def visit_TryExceptStatNode(self, node):
         self.visitchildren(node)
         if node.body.is_terminator and node.else_clause:

tests/errors/w_unreachable.pyx

@@ -31,6 +31,10 @@ def try_except():
     else:
         print 'unreachable'
 
+def infinite_loops():
+    while True:
+        pass
+    print 'Never be here'
 
 _ERRORS = """
 6:4: Unreachable code
@@ -38,4 +42,5 @@ _ERRORS = """
 15:8: Unreachable code
 24:4: Unreachable code
 32:8: Unreachable code
+37:4: Unreachable code
 """