Tests: update some backend tests on enum entries

The enumEntriesIntrinsicMultipleEnums.kt test was supposed to check that
JVM backend generates 3 `$EntriesIntrinsicMappings` classes: for X, for
Y, and for Z. Mappings classes are generated for enums without
`entries`, i.e. Kotlin enums compiled without `EnumEntries` language
feature, and Java enums. The test incorrectly _enabled_ the language
feature for X though, and `$EntriesIntrinsicMappings` for X was
generated anyway because of KT-61208.

To keep the original intention of the test, I'm disabling the language
feature for X, so that it will be considered as enum without `entries`.
KT-61208 will be fixed in a separate commit (with separate tests).

The boxInline and bytecodeText tests changed their meaning when language
feature EnumEntries started to be enabled by default, so those changes
are a continuation to ebd43fc8c0. The behavior did not change after
enabling the feature, once again because of KT-61208.

Also, remove obsolete error suppressions which are no longer needed
after 64c8ce18a0.

compiler/testData/codegen/bytecodeText/enum/enumEntriesMapping.kt

@@ -3,6 +3,7 @@
 // WITH_STDLIB
 
 // MODULE: lib
+// !LANGUAGE: -EnumEntries
 // FILE: MyEnums.kt
 enum class MyEnum {
     N, O

compiler/testData/codegen/bytecodeText/enum/enumEntriesMultiMapping.kt

@@ -3,6 +3,7 @@
 // WITH_STDLIB
 
 // MODULE: lib
+// !LANGUAGE: -EnumEntries
 // FILE: MyEnums.kt
 enum class MyEnum {
     N, O

compiler/testData/codegen/bytecodeText/inline/entriesMappingOnCallSite.kt

@@ -3,6 +3,7 @@
 // WITH_RUNTIME
 
 // MODULE: lib
+// !LANGUAGE: -EnumEntries
 // FILE: 1.kt
 
 enum class X {