Test that attempts to inline with caller or callee in a cgo-generated
file are rejected.

-- go.mod --
module testdata
go 1.12

-- a/a.go --
package a

/*
static void f() {}
*/
import "C"

func a() {
	C.f() //@ inline(re"f", re"cannot inline cgo-generated functions")
	g()   //@ inline(re"g", re`cannot inline calls from files that import "C"`)
}

func g() {
	println()
}

-- a/a2.go --
package a

func b() {
	a() //@ inline(re"a", re"cannot inline cgo-generated functions")
}

func c() {
	b() //@ inline(re"b", result)
}

-- result --
package a

func b() {
	a() //@ inline(re"a", re"cannot inline cgo-generated functions")
}

func c() {
	a() //@ inline(re"b", result)
}