[Interpreter] Add implementations for load immediate bytecodes.

test/unittests/compiler/interpreter-assembler-unittest.h

Index: test/unittests/compiler/interpreter-assembler-unittest.h
diff --git a/test/unittests/compiler/interpreter-assembler-unittest.h b/test/unittests/compiler/interpreter-assembler-unittest.h
index d3e645b27c44616e876a7febcf98be48363fe466..64353ae1288e437611c12858e01a94ddf1d3ef96 100644
--- a/test/unittests/compiler/interpreter-assembler-unittest.h
+++ b/test/unittests/compiler/interpreter-assembler-unittest.h
@@ -38,6 +38,8 @@ class InterpreterAssemblerTest : public TestWithIsolateAndZone {
                            const Matcher<Node*>& base_matcher,
                            const Matcher<Node*>& index_matcher,
                            const Matcher<Node*>& value_matcher);
+    Matcher<Node*> IsBytecodeOperand(int operand);
+    Matcher<Node*> IsBytecodeOperandSignExtended(int operand);
 
     using InterpreterAssembler::call_descriptor;
     using InterpreterAssembler::graph;