Deserialize experimental coroutines as suspend functions/types

but deprecate them for now.
Promote stub version.
 #KT-25623: Fixed

compiler/testData/compileKotlinAgainstCustomBinaries/experimentalCoroutineCallFromRelease/library/experimental.kt

@@ -0,0 +1,27 @@
+suspend fun dummy() {}
+
+class C {
+    suspend fun dummy() = "OK"
+}
+
+class WithNested {
+    class Nested {
+        suspend fun dummy() = "OK"
+    }
+}
+
+class WithInner {
+    inner class Inner {
+        suspend fun dummy() = "OK"
+    }
+}
+
+val c: suspend () -> Unit = {}
+
+class WithTypeParameter<T: suspend() -> Unit> {}
+
+fun returnsSuspend() : suspend() -> Unit = {}
+
+fun builder(c: suspend () -> Unit) {}
+
+fun <T: suspend () -> Unit> withTypeParameter() = {}

compiler/testData/compileKotlinAgainstCustomBinaries/experimentalCoroutineCallFromRelease/output.txt

@@ -0,0 +1,29 @@
+warning: language version 1.3 is experimental, there are no backwards compatibility guarantees for new language and library features
+compiler/testData/compileKotlinAgainstCustomBinaries/experimentalCoroutineCallFromRelease/release.kt:2:5: error: using 'c: suspend () -> Unit' is an error. Experimental coroutine cannot be used with API version 1.3
+    c()
+    ^
+compiler/testData/compileKotlinAgainstCustomBinaries/experimentalCoroutineCallFromRelease/release.kt:3:5: error: using 'constructor WithTypeParameter<T : suspend () -> Unit>()' is an error. Experimental coroutine cannot be used with API version 1.3
+    WithTypeParameter<suspend () -> Unit>()
+    ^
+compiler/testData/compileKotlinAgainstCustomBinaries/experimentalCoroutineCallFromRelease/release.kt:4:5: error: using 'returnsSuspend(): suspend () -> Unit' is an error. Experimental coroutine cannot be used with API version 1.3
+    returnsSuspend()
+    ^
+compiler/testData/compileKotlinAgainstCustomBinaries/experimentalCoroutineCallFromRelease/release.kt:5:5: error: using 'builder(suspend () -> Unit): Unit' is an error. Experimental coroutine cannot be used with API version 1.3
+    builder {}
+    ^
+compiler/testData/compileKotlinAgainstCustomBinaries/experimentalCoroutineCallFromRelease/release.kt:6:5: error: using 'withTypeParameter(): () -> Unit' is an error. Experimental coroutine cannot be used with API version 1.3
+    withTypeParameter<suspend () -> Unit>()
+    ^
+compiler/testData/compileKotlinAgainstCustomBinaries/experimentalCoroutineCallFromRelease/release.kt:8:5: error: using 'dummy(): Unit' is an error. Experimental coroutine cannot be used with API version 1.3
+    dummy()
+    ^
+compiler/testData/compileKotlinAgainstCustomBinaries/experimentalCoroutineCallFromRelease/release.kt:9:9: error: using 'dummy(): String' is an error. Experimental coroutine cannot be used with API version 1.3
+    C().dummy()
+        ^
+compiler/testData/compileKotlinAgainstCustomBinaries/experimentalCoroutineCallFromRelease/release.kt:10:25: error: using 'dummy(): String' is an error. Experimental coroutine cannot be used with API version 1.3
+    WithNested.Nested().dummy()
+                        ^
+compiler/testData/compileKotlinAgainstCustomBinaries/experimentalCoroutineCallFromRelease/release.kt:11:25: error: using 'dummy(): String' is an error. Experimental coroutine cannot be used with API version 1.3
+    WithInner().Inner().dummy()
+                        ^
+COMPILATION_ERROR

compiler/testData/compileKotlinAgainstCustomBinaries/experimentalCoroutineCallFromRelease/release.kt

@@ -0,0 +1,12 @@
+suspend fun callRelease() {
+    c()
+    WithTypeParameter<suspend () -> Unit>()
+    returnsSuspend()
+    builder {}
+    withTypeParameter<suspend () -> Unit>()
+
+    dummy()
+    C().dummy()
+    WithNested.Nested().dummy()
+    WithInner().Inner().dummy()
+}