Support inline suspend functions

A lot of additional work was required to support them:
- Suspension points are being identified by two markers
  instead of one pointing to suspend function call
- Approach with replacing return type of suspend function does not work anymore.
  So we decode suspension return type as an argument for begin marker
- It became necessary to perform variables liveness analysis
  (see comment in org.jetbrains.kotlin.codegen.coroutines.CoroutineTransformerMethodVisitor.spillVariables)

compiler/testData/codegen/box/coroutines/inlineSuspendFunction.kt

@@ -0,0 +1,40 @@
+// WITH_RUNTIME
+class Controller {
+    fun withValue(v: String, x: Continuation<String>) {
+        x.resume(v)
+    }
+
+    suspend inline fun suspendInline(v: String, x: Continuation<String>) {
+        withValue(v, x)
+    }
+
+    suspend inline fun suspendInline(crossinline b: () -> String, x: Continuation<String>) {
+        suspendInline(b(), x)
+    }
+
+    suspend inline fun <reified T : Any> suspendInline(x: Continuation<String>) {
+        suspendInline({ T::class.java.simpleName }, x)
+    }
+}
+
+fun builder(coroutine c: Controller.() -> Continuation<Unit>) {
+    c(Controller()).resume(Unit)
+}
+
+class OK
+
+fun box(): String {
+    var result = ""
+
+    builder {
+        result = suspendInline("56")
+        if (result != "56") throw RuntimeException("fail 1")
+
+        result = suspendInline { "57" }
+        if (result != "57") throw RuntimeException("fail 2")
+
+        result = suspendInline<OK>()
+    }
+
+    return result
+}