Restore writing bytecode version to metadata for LV < 1.5

#KT-45323 Fixed

compiler/frontend.java/src/org/jetbrains/kotlin/load/kotlin/JvmBytecodeBinaryVersion.kt

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.load.kotlin
+
+/**
+ * Bytecode version was in the Kotlin metadata ([Metadata.bytecodeVersion]) since 1.0, but it was never used meaningfully in the compiler,
+ * outside of one very special case regarding experimental coroutines, which is now obsolete.
+ * It is still used for two reasons:
+ * 1) We write the latest observed bytecode version, `1.0.3` (see [INSTANCE]), to class files if metadata version is less than 1.5.
+ *    The reason is that Kotlin compilers of versions 1.0.0-1.3.72 can still read these class files, and they had a strict check which
+ *    results in a compilation error if there's no bytecode version in the `@Metadata` annotation (see KT-45323).
+ *    This will not be needed at the moment when the earliest supported language version becomes 1.5, i.e. in Kotlin 1.7.
+ * 2) It's stored in persistent incremental compilation caches. We can probably simply remove it and increase the cache version there.
+ * Once both these usages are dealt with, this class can be removed.
+ */
+class JvmBytecodeBinaryVersion(vararg numbers: Int) {
+    val major: Int = numbers.getOrNull(0) ?: -1
+    val minor: Int = numbers.getOrNull(1) ?: -1
+    val patch: Int = numbers.getOrNull(2) ?: -1
+
+    fun toArray(): IntArray = intArrayOf(major, minor, patch)
+
+    override fun toString(): String = buildString {
+        append(major)
+        if (minor != -1) {
+            append(".$minor")
+            if (patch != -1) append(".$patch")
+        }
+    }
+
+    companion object {
+        @JvmField
+        val INSTANCE = JvmBytecodeBinaryVersion(1, 0, 3)
+    }
+}