Do not coerce function literals to suspend.

The design is to use `suspend fun` instead of coercion, just as suspend
lambdas.
However, this syntax is not supported in the parser. But this is not a
problem, since the coercion lead to internal compiler error.
As a workaround everybody uses suspend lambdas.
 #KT-24860: Fixed

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -9245,6 +9245,11 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 runTest("compiler/testData/diagnostics/tests/inference/cannotCompleteResolveWithFunctionLiterals.kt");
             }
 
+            @TestMetadata("coerceFunctionLiteralToSuspend.kt")
+            public void testCoerceFunctionLiteralToSuspend() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/inference/coerceFunctionLiteralToSuspend.kt");
+            }
+
             @TestMetadata("completeInferenceIfManyFailed.kt")
             public void testCompleteInferenceIfManyFailed() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/inference/completeInferenceIfManyFailed.kt");