[DO-NOT-MERGE][EXPERIMENT] eagerReplace=false default + no-op MaterializeRuntimeReplaceable

Temporary diagnostic commit to let PR CI surface every test that breaks when
a surviving RuntimeReplaceable reaches whole-stage codegen (materialization
disabled). Must be reverted before merge.

Co-authored-by: Isaac

Author: cloud-fan

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Expression.scala

@@ -480,7 +480,7 @@ trait RuntimeReplaceable extends Expression {
   // codegen by `MaterializeRuntimeReplaceable`. Note that an expression that opts out can still be
   // rewritten eagerly if its `replacement` cannot survive (non-deterministic or unevaluable); see
   // `ReplaceExpressions`.
-  def eagerReplace: Boolean = true
+  def eagerReplace: Boolean = false // EXPERIMENT: flipped default to expose breakage
 
   // `RuntimeReplaceable` expressions are normally rewritten into their `replacement` by the
   // `ReplaceExpressions` rule before execution. However, an expression with `eagerReplace = false`

sql/core/src/main/scala/org/apache/spark/sql/execution/MaterializeRuntimeReplaceable.scala

@@ -17,9 +17,7 @@
 
 package org.apache.spark.sql.execution
 
-import org.apache.spark.sql.catalyst.expressions.RuntimeReplaceable
 import org.apache.spark.sql.catalyst.rules.Rule
-import org.apache.spark.sql.catalyst.trees.TreePattern.RUNTIME_REPLACEABLE
 
 /**
  * Materializes any [[RuntimeReplaceable]] that survived the logical optimizer into its
@@ -33,8 +31,6 @@ import org.apache.spark.sql.catalyst.trees.TreePattern.RUNTIME_REPLACEABLE
  * while Spark whole-stage codegen never sees a `RuntimeReplaceable`.
  */
 object MaterializeRuntimeReplaceable extends Rule[SparkPlan] {
-  override def apply(plan: SparkPlan): SparkPlan = plan.transformUpWithSubqueries {
-    case p if p.expressions.exists(_.containsPattern(RUNTIME_REPLACEABLE)) =>
-      p.mapExpressions(RuntimeReplaceable.unfold)
-  }
+  // EXPERIMENT: no-op so surviving RuntimeReplaceable reaches whole-stage codegen.
+  override def apply(plan: SparkPlan): SparkPlan = plan
 }