Expose a lower bound of malloc'd memory via heap statistics

test/unittests/wasm/encoder-unittest.cc

Index: test/unittests/wasm/encoder-unittest.cc
diff --git a/test/unittests/wasm/encoder-unittest.cc b/test/unittests/wasm/encoder-unittest.cc
index f7c54591f9392026c29e059dbb028ed0f63fb0fa..a1c4ece0b2f8c4c3caa690348281bada122e7fb8 100644
--- a/test/unittests/wasm/encoder-unittest.cc
+++ b/test/unittests/wasm/encoder-unittest.cc
@@ -52,7 +52,7 @@ class EncoderTest : public TestWithZone {
 
 
 TEST_F(EncoderTest, Function_Builder_Variable_Indexing) {
-  Zone zone;
+  ZoneForTesting zone;
   WasmModuleBuilder* builder = new (&zone) WasmModuleBuilder(&zone);
   uint16_t f_index = builder->AddFunction();
   WasmFunctionBuilder* function = builder->FunctionAt(f_index);
@@ -90,7 +90,7 @@ TEST_F(EncoderTest, Function_Builder_Variable_Indexing) {
 
 
 TEST_F(EncoderTest, Function_Builder_Indexing_Variable_Width) {
-  Zone zone;
+  ZoneForTesting zone;
   WasmModuleBuilder* builder = new (&zone) WasmModuleBuilder(&zone);
   uint16_t f_index = builder->AddFunction();
   WasmFunctionBuilder* function = builder->FunctionAt(f_index);
@@ -109,7 +109,7 @@ TEST_F(EncoderTest, Function_Builder_Indexing_Variable_Width) {
 }
 
 TEST_F(EncoderTest, Function_Builder_Block_Variable_Width) {
-  Zone zone;
+  ZoneForTesting zone;
   WasmModuleBuilder* builder = new (&zone) WasmModuleBuilder(&zone);
   uint16_t f_index = builder->AddFunction();
   WasmFunctionBuilder* function = builder->FunctionAt(f_index);
@@ -123,7 +123,7 @@ TEST_F(EncoderTest, Function_Builder_Block_Variable_Width) {
 }
 
 TEST_F(EncoderTest, Function_Builder_EmitEditableVarIntImmediate) {
-  Zone zone;
+  ZoneForTesting zone;
   WasmModuleBuilder* builder = new (&zone) WasmModuleBuilder(&zone);
   uint16_t f_index = builder->AddFunction();
   WasmFunctionBuilder* function = builder->FunctionAt(f_index);
@@ -139,7 +139,7 @@ TEST_F(EncoderTest, Function_Builder_EmitEditableVarIntImmediate) {
 }
 
 TEST_F(EncoderTest, Function_Builder_EmitEditableVarIntImmediate_Locals) {
-  Zone zone;
+  ZoneForTesting zone;
   WasmModuleBuilder* builder = new (&zone) WasmModuleBuilder(&zone);
   uint16_t f_index = builder->AddFunction();
   WasmFunctionBuilder* function = builder->FunctionAt(f_index);