[wasm] Add test for element section with non-zero table indices

R=mstarzinger@chromium.org

Bug: v8:7581
Change-Id: Id8b9c3596eb6caf5ee7048a87a676a85dba0c5dc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1520711
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60239}

test/mjsunit/wasm/multi-table-element-section.js

+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --expose-wasm --experimental-wasm-anyref
+
+load("test/mjsunit/wasm/wasm-module-builder.js");
+
+const value1 = 11;
+const value2 = 22;
+const value3 = 46;
+const value4 = 57;
+const value5 = 13;
+
+// The offsets for the initialization of tables. The segement for table2 should
+// overlap with the segment of table1, because table2 is actually the imported
+// table1.
+const offset1 = 2;
+const offset2 = offset1 + 1;
+const offset3 = 4;
+const offset4 = 1;
+
+const instance_for_import = (function() {
+    const builder_for_import = new WasmModuleBuilder();
+    const t1 = builder_for_import.addTable(kWasmAnyFunc, 15, 15)
+        .exportAs("table").index;
+    const f1 = builder_for_import.addFunction('f1', kSig_i_v)
+        .addBody([kExprI32Const, value1]).index;
+    const f2 = builder_for_import.addFunction('f2', kSig_i_v)
+        .addBody([kExprI32Const, value2]).index;
+
+    builder_for_import.addElementSegment(t1, offset1, false, [f1, f2], false);
+    const instance_for_import = builder_for_import.instantiate();
+    const table1 = instance_for_import.exports.table;
+    assertEquals(value1, table1.get(offset1)());
+    assertEquals(value2, table1.get(offset1 + 1)());
+    return instance_for_import;
+})();
+
+const builder = new WasmModuleBuilder();
+
+const t2 = builder.addImportedTable("exports", "table", 15, 15);
+builder.addExportOfKind("table2", kExternalTable, t2);
+const t3 = builder.addTable(kWasmAnyFunc, 10).exportAs("table3").index;
+const t4 = builder.addTable(kWasmAnyFunc, 12).exportAs("table4").index;
+
+const f3 = builder.addFunction('f3', kSig_i_v)
+                  .addBody([kExprI32Const, value3]).index;
+const f4 = builder.addFunction('f4', kSig_i_v)
+                  .addBody([kExprI32Const, value4]).index;
+const f5 = builder.addFunction('f5', kSig_i_v)
+                  .addBody([kExprI32Const, value5]).index;
+
+
+builder.addElementSegment(t2, offset2, false, [f3, f4], false);
+builder.addElementSegment(t3, offset3, false, [f5, f4], false);
+builder.addElementSegment(t4, offset4, false, [f3, f5], false);
+// Add one more overlapping offset
+builder.addElementSegment(t4, offset4 + 1, false, [f4, f3], false);
+
+const instance = builder.instantiate(instance_for_import);
+// table2 == table1
+const table2 = instance.exports.table2;
+const table3 = instance.exports.table3;
+const table4 = instance.exports.table4;
+// table1 == table2
+assertEquals(value1, table2.get(offset1)());
+assertEquals(value3, table2.get(offset2)());
+assertEquals(value4, table2.get(offset2 + 1)());
+
+assertEquals(value5, table3.get(offset3)());
+assertEquals(value4, table3.get(offset3 + 1)());
+
+assertEquals(value3, table4.get(offset4)());
+assertEquals(value4, table4.get(offset4 + 1)());
+assertEquals(value3, table4.get(offset4 + 2)());