Revert of [builtins] Introduce proper Float64Exp operator.

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index 048875732fa5f0a807f74cc76bfad5fa45367a10..7b9b8e1e1a2e1ef3c9a8e5c84038bf0d815c80d2 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -1138,8 +1138,6 @@
       return MarkAsFloat64(node), VisitFloat64Atan(node);
     case IrOpcode::kFloat64Atan2:
       return MarkAsFloat64(node), VisitFloat64Atan2(node);
-    case IrOpcode::kFloat64Exp:
-      return MarkAsFloat64(node), VisitFloat64Exp(node);
     case IrOpcode::kFloat64Log:
       return MarkAsFloat64(node), VisitFloat64Log(node);
     case IrOpcode::kFloat64Log1p:
@@ -1261,10 +1259,6 @@
   VisitFloat64Ieee754Binop(node, kIeee754Float64Atan2);
 }
 
-void InstructionSelector::VisitFloat64Exp(Node* node) {
-  VisitFloat64Ieee754Unop(node, kIeee754Float64Exp);
-}
-
 void InstructionSelector::VisitFloat64Log(Node* node) {
   VisitFloat64Ieee754Unop(node, kIeee754Float64Log);
 }