[Test] Use runAsync to invoke async cc test.

Author: nate-chandler

test/IRGen/async/run-call-struct_five_bools-to-void.sil

@@ -41,6 +41,9 @@ entry(%pack : $Pack):
   return %printGeneric_result1 : $()
 }
 
+// Defined in _Concurrency
+sil public_external @$s12_Concurrency8runAsyncyyyyYcF : $@convention(thin) (@guaranteed @async @callee_guaranteed () -> ()) -> ()
+
 // CHECK-LL: define{{( dllexport)?}}{{( protected)?}} swiftcc void @test_case(%swift.task* {{%[0-9]+}}, %swift.executor* {{%[0-9]+}}, %swift.context* {{%[0-9]+}}) {{#[0-9]*}} {
 sil @test_case : $@async @convention(thin) () -> () {
 
@@ -64,12 +67,13 @@ sil @test_case : $@async @convention(thin) () -> () {
 
 sil @main : $@async @convention(c) (Int32, UnsafeMutablePointer<Optional<UnsafeMutablePointer<Int8>>>) -> Int32 {
 bb0(%0 : $Int32, %1 : $UnsafeMutablePointer<Optional<UnsafeMutablePointer<Int8>>>):
-  
-  %test_case = function_ref @test_case : $@convention(thin) @async () -> ()
-  %result = apply %test_case() : $@convention(thin) @async () -> ()
 
-  %2 = integer_literal $Builtin.Int32, 0
-  %3 = struct $Int32 (%2 : $Builtin.Int32)
-  return %3 : $Int32
-}
+  %2 = function_ref @test_case : $@convention(thin) @async () -> ()
+  %3 = thin_to_thick_function %2 : $@convention(thin) @async () -> () to $@async @callee_guaranteed () -> ()
+  %4 = function_ref @$s12_Concurrency8runAsyncyyyyYcF : $@convention(thin) (@guaranteed @async @callee_guaranteed () -> ()) -> ()
+  %5 = apply %4(%3) : $@convention(thin) (@guaranteed @async @callee_guaranteed () -> ()) -> ()
 
+  %6 = integer_literal $Builtin.Int32, 0
+  %7 = struct $Int32 (%6 : $Builtin.Int32)
+  return %7 : $Int32
+}