Revert "Get rid of 'BRIDGE' flag on $default functions"

Removed bridge flag triggers problem with Spring Boot: KT-23973
 This reverts commit cdcb651

 #KT-23973 Fixed

compiler/testData/writeFlags/function/withDefaultArguments/funInClass.kt

@@ -4,4 +4,4 @@ class MyClass() {
 
 // TESTED_OBJECT_KIND: function
 // TESTED_OBJECTS: MyClass, test$default
-// FLAGS: ACC_PUBLIC, ACC_STATIC, ACC_SYNTHETIC
+// FLAGS: ACC_PUBLIC, ACC_STATIC, ACC_BRIDGE, ACC_SYNTHETIC

compiler/testData/writeFlags/function/withDefaultArguments/funInClassObject.kt

@@ -6,4 +6,4 @@ class MyClass() {
 
 // TESTED_OBJECT_KIND: function
 // TESTED_OBJECTS: MyClass$Companion, test$default
-// FLAGS: ACC_PUBLIC, ACC_STATIC, ACC_SYNTHETIC
+// FLAGS: ACC_PUBLIC, ACC_STATIC, ACC_BRIDGE, ACC_SYNTHETIC

compiler/testData/writeFlags/function/withDefaultArguments/inlineOnlyFunInClass.kt

@@ -7,4 +7,4 @@ class MyClass() {
 
 // TESTED_OBJECT_KIND: function
 // TESTED_OBJECTS: MyClass, test$default
-// FLAGS: ACC_STATIC, ACC_SYNTHETIC
+// FLAGS: ACC_STATIC, ACC_BRIDGE, ACC_SYNTHETIC

compiler/testData/writeFlags/function/withDefaultArguments/reifiedFunInClass.kt

@@ -4,4 +4,4 @@ class MyClass() {
 
 // TESTED_OBJECT_KIND: function
 // TESTED_OBJECTS: MyClass, test$default
-// FLAGS: ACC_STATIC, ACC_SYNTHETIC
+// FLAGS: ACC_STATIC, ACC_BRIDGE, ACC_SYNTHETIC

compiler/testData/writeFlags/function/withDefaultArguments/topLevelFun.kt

@@ -2,4 +2,4 @@ fun test(s: String = "") {}
 
 // TESTED_OBJECT_KIND: function
 // TESTED_OBJECTS: TopLevelFunKt, test$default
-// FLAGS: ACC_PUBLIC, ACC_STATIC, ACC_SYNTHETIC
+// FLAGS: ACC_PUBLIC, ACC_STATIC, ACC_BRIDGE, ACC_SYNTHETIC