[wasm] Fix -Wsign-compare warnings.

src/wasm/wasm-module.cc

Index: src/wasm/wasm-module.cc
diff --git a/src/wasm/wasm-module.cc b/src/wasm/wasm-module.cc
index 179af57ac6d626c06d0fc315d2aa38826b37892b..e033231f0e2b67af4ef50fd25d7ef28486dc43d6 100644
--- a/src/wasm/wasm-module.cc
+++ b/src/wasm/wasm-module.cc
@@ -1470,7 +1470,7 @@ class WasmInstanceBuilder {
 
           // TODO(titzer): import table size must match exactly for now.
           int table_size = table_instance.js_wrappers->length();
-          if (table_size != table.min_size) {
+          if (table_size != static_cast<int>(table.min_size)) {
             thrower_->TypeError(
                 "table import %d is wrong size (%d), expected %u", index,
                 table_size, table.min_size);