Don't override compilation freeCompilerArgs in link task

Calling '.addAll()' was replacing convention value leading for inability
to add/modify Kotlin/Native link task freeCompilerArgs via
KotlinCompilation.options.freeCompilerArgs. For now convention
was replaced by normal value.

^KT-56280 Fixed

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/native/KotlinNativeLinkIT.kt

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.gradle.native
 import org.gradle.util.GradleVersion
 import org.jetbrains.kotlin.gradle.testbase.*
 import org.junit.jupiter.api.DisplayName
+import kotlin.io.path.appendText
 
 @DisplayName("KotlinNativeLink task tests")
 @NativeGradlePluginTests
@@ -20,4 +21,50 @@ internal class KotlinNativeLinkIT : KGPBaseTest() {
             build("tasks")
         }
     }
+
+    @DisplayName("KT-56280: should propagate freeCompilerArgs from compilation")
+    @GradleTest
+    fun shouldUseCompilationFreeCompilerArgs(gradleVersion: GradleVersion) {
+        nativeProject("native-link-simple", gradleVersion) {
+            buildGradle.appendText(
+                """
+                |
+                |kotlin {
+                |    targets.named("host").configure {
+                |        binaries.executable()
+                |    }
+                |    
+                |    targets.withType(org.jetbrains.kotlin.gradle.plugin.mpp.KotlinNativeTarget.class) {
+                |        compilations.main.kotlinOptions {
+                |            freeCompilerArgs += ["-e", "main"]
+                |        }
+                |    }
+                |}
+                """.trimMargin()
+            )
+
+            build("linkReleaseExecutableHost") {
+                val linkTaskOutput = output
+                    .substringAfter("Task :linkReleaseExecutableHost")
+                    .substringBefore("Task :linkHost")
+                assert(linkTaskOutput.isNotEmpty()) {
+                    "Could not get :linkReleaseExecutableHost task output!"
+                }
+
+                val args = linkTaskOutput
+                    .substringAfterLast("Transformed arguments = [")
+                    .substringBefore("]")
+                    .lines()
+                    .map { it.trim() }
+                assert(
+                    args.isNotEmpty() &&
+                            args.contains("-e") &&
+                            args.contains("main")
+                ) {
+                    printBuildOutput()
+                    "Link task arguments does not contain '-e main'!"
+                }
+            }
+        }
+    }
 }