Revert "[FIRRTL] Enable Wire Elimination (#7073)"

[jackkoenig]

This reverts commit f5a0969.

Wire Elimination is causing some issues where wire names are overriding register names in an undesirable way. I think we just need to tweak our heuristic a bit then re-enable, but we would like to get a firtool release out ASAP so I think we should revert temporarily.

Example FIRRTL:

FIRRTL version 3.3.0
circuit Foo :
  module Foo :
    input clock : Clock
    input reset : UInt<1>
    input in : { fizz : { foo : UInt<8>}, buzz : { foo : UInt<8>}}
    output out1 : { foo : UInt<8>}
    output out2 : { foo : UInt<8>}

    reg myReg : { fizz : { foo : UInt<8>}, buzz : { foo : UInt<8>}}, clock
    wire w1 : { foo : UInt<8>}
    wire w2 : { foo : UInt<8>}
    connect myReg.buzz.foo, in.buzz.foo
    connect myReg.fizz.foo, in.fizz.foo
    connect w1.foo, myReg.fizz.foo
    connect w2.foo, myReg.buzz.foo
    connect out1.foo, w1.foo
    connect out2.foo, w2.foo

Before this revert:

// Generated by CIRCT firtool-1.76.0-171-g961bad58f
module Foo(
  input        clock,
               reset,
  input  [7:0] in_fizz_foo,
               in_buzz_foo,
  output [7:0] out1_foo,
               out2_foo
);

  reg [7:0] w1_foo;
  reg [7:0] w2_foo;
  always @(posedge clock) begin
    w1_foo <= in_fizz_foo;
    w2_foo <= in_buzz_foo;
  end // always @(posedge)
  assign out1_foo = w1_foo;
  assign out2_foo = w2_foo;
endmodule

After this revert (and also the behavior on firtool 1.76.0 and previous versions):

// Generated by CIRCT firtool-1.76.0-172-gd6f349bed
module Foo(
  input        clock,
               reset,
  input  [7:0] in_fizz_foo,
               in_buzz_foo,
  output [7:0] out1_foo,
               out2_foo
);

  reg [7:0] myReg_fizz_foo;
  reg [7:0] myReg_buzz_foo;
  always @(posedge clock) begin
    myReg_fizz_foo <= in_fizz_foo;
    myReg_buzz_foo <= in_buzz_foo;
  end // always @(posedge)
  assign out1_foo = myReg_fizz_foo;
  assign out2_foo = myReg_buzz_foo;
endmodule

[dobios]

I don't see any breaking issue with doing this so LGTM!

[uenoku]

LGTM