Verilator thinks ~|a and ~(|a) are the same thing

The following module should return 4'b0000 or 4'b0001 but Verilator GIT fb4928b returns 4'b1111 or 4'b1110 instead.

module issue_034(a, y);
  input [3:0] a;
  output [3:0] y;
  assign y = ~|a;
endmodule

Note: The ~| in ~|a is the nor reduction operator. This is different from ~(|a).

Crosscheck: Vivado 2013.4, XST 14.7, Quartus 13.1, Xsim 2013.4 and Modelsim 10.1d implement this correctly.

Self-contained test case: test005.v, test005.cc, test005.sh

History:
2014-04-09 Reported as Issue #736
2014-04-06 Fixed in GIT commit d04eb97