Fix bootstrap failure by disabling problematic optimizations

The eliminate_dead_instructions() and fold_constant_branches() functions
were corrupting the instruction stream and causing bootstrap failures.
These functions appear to have issues with linked list manipulation
that cause memory corruption during stage2 compilation.

Commenting them out for now restores bootstrap capability while
keeping all other safe optimizations active.

Author: jserv

src/peephole.c

@@ -960,8 +960,9 @@ void peephole(void)
 {
     for (func_t *func = FUNC_LIST.head; func; func = func->next) {
         /* Phase 1: Dead code elimination complementing SCCP results */
-        eliminate_dead_instructions(func);
-        fold_constant_branches(func);
+        /* FIXME: These functions break bootstrap, commenting out for now */
+        /* eliminate_dead_instructions(func); */
+        /* fold_constant_branches(func); */
 
         /* Phase 2: Local peephole optimizations on post-register-allocation IR
          */