Add test for ExtractTupleElementInstruction.getResultType()

ql/test/library-tests/semmle/go/IR/test.expected

@@ -0,0 +1,6 @@
+| test.go:9:2:9:16 | ... := ...[0] | bool |
+| test.go:9:2:9:16 | ... := ...[1] | bool |
+| test.go:15:2:15:20 | ... := ...[0] | string |
+| test.go:15:2:15:20 | ... := ...[1] | bool |
+| test.go:21:2:21:22 | ... := ...[0] | string |
+| test.go:21:2:21:22 | ... := ...[1] | bool |

ql/test/library-tests/semmle/go/IR/test.go

@@ -0,0 +1,23 @@
+package test
+
+import (
+	"fmt"
+)
+
+func testChannel() {
+	var ch chan bool
+	got, ok := <-ch
+	fmt.Printf("%v %v", got, ok)
+}
+
+func testMap() {
+	var m map[string]string
+	got, ok := m["key"]
+	fmt.Printf("%v %v", got, ok)
+}
+
+func testTypeAssert() {
+	var i interface{}
+	got, ok := i.(string)
+	fmt.Printf("%v %v", got, ok)
+}

ql/test/library-tests/semmle/go/IR/test.ql

@@ -0,0 +1,4 @@
+import go
+
+from IR::ExtractTupleElementInstruction extract
+select extract, extract.getResultType()