Verific sign handling in {N{...}} and {...} again

The following test case is similar to issue_000 (VIPER Issue #8510). Verific 463_32_140722 passes issue_000 but fails to implement y1 and y5 correctly in the following module:

module issue_054(a, y0, y1, y2, y3, y4, y5, y6, y7);
  input signed [1:0] a;
  output [7:0] y0, y1, y2, y3, y4, y5, y6, y7;

  assign y0 = {1'sb1};
  assign y1 = {1{1'sb1}};
  assign y2 = {1'sb1, 1'sb1};
  assign y3 = {2{1'sb1}};
  assign y4 = {a};
  assign y5 = {1{a}};
  assign y6 = {a, a};
  assign y7 = {2{a}};
endmodule

As in issue_000 the problem is that the replication operator fails to set the expression to unsigned (I suppose because it is optimized away), leading to signed instead of unsigned extension to 8 bits.

History:
2014-07-23 Reported bug to Verific support
2015-05-20 Fixed in Verific 482_32_150519