Update Kotlin to 1.6.20 and release

Author: tschuchortdev

README.md

@@ -97,7 +97,7 @@ Add dependency to your module's `build.gradle` file:
 ```Groovy
 dependencies {
         // ...
-	testImplementation 'com.github.tschuchortdev:kotlin-compile-testing:1.4.7'
+	testImplementation 'com.github.tschuchortdev:kotlin-compile-testing:1.4.8'
 }
 ```
 
@@ -109,7 +109,7 @@ Kotlin-Compile-Testing is compatible with all _local_ compiler versions. It does
 
 However, if your project or any of its dependencies depend directly on compiler artifacts such as `kotlin-compiler-embeddable` or `kotlin-annotation-processing-embeddable` then they have to be the same version as the one used by Kotlin-Compile-Testing or there will be a transitive dependency conflict.
 
-- Current `kotlin-compiler-embeddable` version: `1.6.10`
+- Current `kotlin-compiler-embeddable` version: `1.6.20`
 
 Because the internal APIs of the Kotlin compiler often change between versions, we can only support one `kotlin-compiler-embeddable` version at a time. 
 
@@ -121,7 +121,7 @@ To test KSP processors, you need to use the KSP dependency:
 
 ```Groovy
 dependencies {
-    testImplementation 'com.github.tschuchortdev:kotlin-compile-testing-ksp:1.4.7'
+    testImplementation 'com.github.tschuchortdev:kotlin-compile-testing-ksp:1.4.8'
 }
 ```
 

build.gradle

@@ -1,6 +1,6 @@
 buildscript {
     ext.kotlin_version = '1.6.20'
-    ext.embedded_kotlin_version =  '1.6.20-M1'//'1.6.20-M1-1.0.2'
+    ext.embedded_kotlin_version =  '1.6.20'
 
     repositories {
         mavenCentral()

core/src/main/kotlin/com/tschuchort/compiletesting/AbstractKotlinCompilation.kt

@@ -273,6 +273,7 @@ abstract class AbstractKotlinCompilation<A : CommonCompilerArguments> internal c
 
 internal fun convertKotlinExitCode(code: ExitCode) = when(code) {
     ExitCode.OK -> KotlinCompilation.ExitCode.OK
+    ExitCode.OOM_ERROR,
     ExitCode.INTERNAL_ERROR -> KotlinCompilation.ExitCode.INTERNAL_ERROR
     ExitCode.COMPILATION_ERROR -> KotlinCompilation.ExitCode.COMPILATION_ERROR
     ExitCode.SCRIPT_EXECUTION_ERROR -> KotlinCompilation.ExitCode.SCRIPT_EXECUTION_ERROR

gradle.properties

@@ -4,7 +4,7 @@ kotlin.incremental=false
 kapt.include.compile.classpath=false
 
 GROUP=com.github.tschuchortdev
-VERSION_NAME=1.4.8-SNAPSHOT
+VERSION_NAME=1.4.8
 POM_DESCRIPTION=A library that enables testing of Kotlin annotation processors, compiler plugins and code generation.
 POM_INCEPTION_YEAR=2019
 POM_URL=https\://github.com/tschuchortdev/kotlin-compile-testing