Allow to read metadata 2.0 from version 1.8

compiler/testData/compileKotlinAgainstCustomBinaries/oldJvmAgainstFir/output.txt

@@ -1,10 +1,8 @@
-error: incompatible classes were found in dependencies. Remove them from the classpath or use '-Xskip-metadata-version-check' to suppress errors
+error: pre-release classes were found in dependencies. Remove them from the classpath, recompile with a release compiler or use '-Xskip-prerelease-check' to suppress errors
-$TMP_DIR$/library.jar!/META-INF/main.kotlin_module: error: module was compiled with an incompatible version of Kotlin. The binary version of its metadata is 2.0.0, expected version is $ABI_VERSION$.
+compiler/testData/compileKotlinAgainstCustomBinaries/oldJvmAgainstFir/source.kt:4:5: error: class 'lib.AKt' is compiled by a pre-release version of Kotlin and cannot be loaded by this version of the compiler
-compiler/testData/compileKotlinAgainstCustomBinaries/oldJvmAgainstFir/source.kt:4:5: error: unresolved reference: get
     get { Box("OK").value }
     ^
-compiler/testData/compileKotlinAgainstCustomBinaries/oldJvmAgainstFir/source.kt:4:11: error: class 'lib.Box' was compiled with an incompatible version of Kotlin. The binary version of its metadata is 2.0.0, expected version is $ABI_VERSION$.
+compiler/testData/compileKotlinAgainstCustomBinaries/oldJvmAgainstFir/source.kt:4:11: error: class 'lib.Box' is compiled by a pre-release version of Kotlin and cannot be loaded by this version of the compiler
-The class is loaded from $TMP_DIR$/library.jar!/lib/Box.class
     get { Box("OK").value }
           ^
 COMPILATION_ERROR

compiler/testData/compileKotlinAgainstCustomBinaries/oldJvmAgainstFirWithStableAbi/output.txt

@@ -1 +1,8 @@
-OK
+error: pre-release classes were found in dependencies. Remove them from the classpath, recompile with a release compiler or use '-Xskip-prerelease-check' to suppress errors
+compiler/testData/compileKotlinAgainstCustomBinaries/oldJvmAgainstFirWithStableAbi/source.kt:4:5: error: class 'lib.AKt' is compiled by a pre-release version of Kotlin and cannot be loaded by this version of the compiler
+    get { Box("OK").value }
+    ^
+compiler/testData/compileKotlinAgainstCustomBinaries/oldJvmAgainstFirWithStableAbi/source.kt:4:11: error: class 'lib.Box' is compiled by a pre-release version of Kotlin and cannot be loaded by this version of the compiler
+    get { Box("OK").value }
+          ^
+COMPILATION_ERROR

compiler/testData/compileKotlinAgainstCustomBinaries/oldJvmAgainstFirWithStableAbiAndNoPrereleaseCheck/library/a.kt

@@ -0,0 +1,5 @@
+package lib
+
+class Box(val value: String)
+
+inline fun <T> get(block: () -> T): T = block()

compiler/testData/compileKotlinAgainstCustomBinaries/oldJvmAgainstFirWithStableAbiAndNoPrereleaseCheck/output.txt

@@ -0,0 +1 @@
+OK

compiler/testData/compileKotlinAgainstCustomBinaries/oldJvmAgainstFirWithStableAbiAndNoPrereleaseCheck/source.kt

@@ -0,0 +1,5 @@
+import lib.*
+
+fun main() {
+    get { Box("OK").value }
+}

compiler/tests/org/jetbrains/kotlin/jvm/compiler/CompileKotlinAgainstCustomBinariesTest.kt

@@ -697,12 +697,15 @@ class CompileKotlinAgainstCustomBinariesTest : AbstractKotlinCompilerIntegration
     }
 
     fun testOldJvmAgainstFirWithStableAbi() {
-        // TODO: looks like now it's not possible to compile library with version 2.0 to be able to compile against it without additional flags
-        // Should we delete this test?
         val library = compileLibrary("library", additionalOptions = listOf("-language-version", "2.0", "-Xabi-stability=stable"))
         compileKotlin("source.kt", tmpdir, listOf(library))
     }
 
+    fun testOldJvmAgainstFirWithStableAbiAndNoPrereleaseCheck() {
+        val library = compileLibrary("library", additionalOptions = listOf("-language-version", "2.0", "-Xabi-stability=stable"))
+        compileKotlin("source.kt", tmpdir, listOf(library), additionalOptions = listOf("-Xskip-prerelease-check"))
+    }
+
     fun testOldJvmAgainstFirWithAllowUnstableDependencies() {
         val library = compileLibrary("library", additionalOptions = listOf("-language-version", "2.0"))
         compileKotlin("source.kt", tmpdir, listOf(library), additionalOptions = listOf("-Xallow-unstable-dependencies", "-Xskip-metadata-version-check"))

core/metadata.jvm/src/org/jetbrains/kotlin/metadata/jvm/deserialization/JvmMetadataVersion.kt

@@ -19,6 +19,8 @@ class JvmMetadataVersion(versionArray: IntArray, val isStrictSemantics: Boolean)
     }
 
     fun isCompatible(metadataVersionFromLanguageVersion: JvmMetadataVersion): Boolean {
+        // Special case for bootstrap: 1.8 can read 2.0
+        if (major == 2 && minor == 0 && INSTANCE.major == 1 && INSTANCE.minor == 8) return true
         // * Compiler of deployVersion X (INSTANCE) with LV Y (metadataVersionFromLanguageVersion)
         //   * can read metadata with version <= max(X+1, Y)
         val forwardCompatibility = if (isStrictSemantics) INSTANCE else INSTANCE_NEXT