[Bug rtl-optimization/116336] New: [14/15 Regression] LRA causes a compare debug with uninitialized variable

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116336

            Bug ID: 116336
           Summary: [14/15 Regression] LRA causes a compare debug with
                    uninitialized variable
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Keywords: compare-debug-failure
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---
            Target: x86_64-linux-gnu

Take:
```
double duk_js_execute_bytecode_duk__tv_0_0;
double duk_double_div();
void duk_handle_call_unprotected();
void duk_js_execute_bytecode() {
  double du_0;
  long opcode_shifted;
  switch (opcode_shifted)
  case 2:
    du_0 = duk_double_div();
  duk_js_execute_bytecode_duk__tv_0_0 = du_0;
  duk_handle_call_unprotected();
  duk_js_execute_bytecode();
}
```

`-O2 -gno-statement-frontiers -fcompare-debug` will show a compare debug
failure.

Note opcode_shifted and du_0 need to be uninitialized.