Revert of [turbofan] Correct regalloc blocked register behavior

src/compiler/register-allocator.cc

Index: src/compiler/register-allocator.cc
diff --git a/src/compiler/register-allocator.cc b/src/compiler/register-allocator.cc
index 5da43c0c457d920a2739efd42368f777b59c0105..5515843612dd12759c846a7601f4e66fc806a8e7 100644
--- a/src/compiler/register-allocator.cc
+++ b/src/compiler/register-allocator.cc
@@ -3278,27 +3278,8 @@
                                                    register_use->pos())) {
       SpillBetween(current, current->Start(), register_use->pos());
     } else {
-      // We can't spill up to the first register use, because there is no gap
-      // where the fill before the register use may happen. This happens when
-      // there is high register pressure, we are at the beginning of an
-      // instruction, we are the input to that instruction, and we can't hold
-      // on to the register past the instruction (we likely lose due to an
-      // output or a temp).
-      // We give the `reg` register to this range, but then we need to spill
-      // until the next register use, if any.
-      LifetimePosition after_this_reg_use = register_use->pos().NextFullStart();
-      DCHECK_LT(after_this_reg_use, current->End());
-
-      const UsePosition* next_reg_pos = register_use->next();
-      for (; next_reg_pos != nullptr; next_reg_pos = next_reg_pos->next()) {
-        if (next_reg_pos->type() == UsePositionType::kRequiresRegister) break;
-      }
       SetLiveRangeAssignedRegister(current, reg);
-      if (next_reg_pos == nullptr) {
-        SpillAfter(current, after_this_reg_use);
-      } else {
-        SpillBetween(current, after_this_reg_use, next_reg_pos->pos());
-      }
+      SplitAndSpillIntersecting(current);
     }
     return;
   }