Write patch version for VersionRequirement correctly

compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt

@@ -615,7 +615,7 @@ class DescriptorSerializer private constructor(
 
         val major = matchResult.groupValues.getOrNull(1)?.toIntOrNull() ?: return null
         val minor = matchResult.groupValues.getOrNull(2)?.toIntOrNull() ?: 0
-        val patch = matchResult.groupValues.getOrNull(3)?.toIntOrNull() ?: 0
+        val patch = matchResult.groupValues.getOrNull(4)?.toIntOrNull() ?: 0
 
         val proto = ProtoBuf.VersionRequirement.newBuilder()
         VersionRequirement.Version(major, minor, patch).encode(

compiler/testData/versionRequirement/patchVersion.kt

@@ -0,0 +1,7 @@
+@file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+package test
+
+import kotlin.internal.RequireKotlin
+
+@RequireKotlin("1.1.50", level = DeprecationLevel.HIDDEN)
+class Klass

compiler/tests/org/jetbrains/kotlin/serialization/VersionRequirementTest.kt

@@ -139,4 +139,10 @@ class VersionRequirementTest : TestCaseWithTmpdir() {
                "test.property"
        )
     }
+
+    fun testPatchVersion() {
+        doTest(VersionRequirement.Version(1, 1, 50), DeprecationLevel.HIDDEN, null, ProtoBuf.VersionRequirement.VersionKind.LANGUAGE_VERSION, null,
+               "test.Klass"
+        )
+    }
 }