Use relative paths in stdlib klib artifacts

Intentionally use doFirst section to trick gradle and not affect
inputs with absolute path usage.

Old behaviour can be returned by kotlin.build.use.absolute.paths.in.klib
in local.properties

Should be removed after KT-50876 fix.

^KTI-730 In Progress

libraries/kotlin.test/js-ir/build.gradle.kts

@@ -52,6 +52,12 @@ tasks.withType<KotlinCompile<*>>().configureEach {
         "-opt-in=kotlin.ExperimentalMultiplatform",
         "-opt-in=kotlin.contracts.ExperimentalContracts"
     )
+
+    doFirst {
+        kotlinOptions.freeCompilerArgs += listOfNotNull(
+            "-Xklib-relative-path-base=$buildDir".takeIf { !kotlinBuildProperties.getBoolean("kotlin.build.use.absolute.paths.in.klib") }
+        )
+    }
 }
 
 tasks.named("compileKotlinJs") {

libraries/stdlib/js-ir/build.gradle.kts

@@ -143,6 +143,12 @@ tasks.withType<KotlinCompile<*>>().configureEach {
         "-opt-in=kotlin.ExperimentalUnsignedTypes",
         "-opt-in=kotlin.ExperimentalStdlibApi"
     )
+
+    doFirst {
+        kotlinOptions.freeCompilerArgs += listOfNotNull(
+            "-Xklib-relative-path-base=$buildDir".takeIf { !kotlinBuildProperties.getBoolean("kotlin.build.use.absolute.paths.in.klib") }
+        )
+    }
 }
 
 val compileKotlinJs by tasks.existing(KotlinCompile::class) {