--- a/js/src/wasm/AsmJS.cpp
+++ b/js/src/wasm/AsmJS.cpp
@@ -248,24 +248,24 @@ class AsmJSImport
 
 typedef Vector<AsmJSImport, 0, SystemAllocPolicy> AsmJSImportVector;
 
 // An AsmJSExport logically extends Export with the extra information needed for
 // an asm.js exported function, viz., the offsets in module's source chars in
 // case the function is toString()ed.
 class AsmJSExport
 {
-    uint32_t funcIndex_;
+    uint32_t funcIndex_ = 0;
 
     // All fields are treated as cacheable POD:
-    uint32_t startOffsetInModule_;  // Store module-start-relative offsets
-    uint32_t endOffsetInModule_;    // so preserved by serialization.
+    uint32_t startOffsetInModule_ = 0;  // Store module-start-relative offsets
+    uint32_t endOffsetInModule_ = 0;    // so preserved by serialization.
 
   public:
-    AsmJSExport() { PodZero(this); }
+    AsmJSExport() = default;
     AsmJSExport(uint32_t funcIndex, uint32_t startOffsetInModule, uint32_t endOffsetInModule)
       : funcIndex_(funcIndex),
         startOffsetInModule_(startOffsetInModule),
         endOffsetInModule_(endOffsetInModule)
     {}
     uint32_t funcIndex() const {
         return funcIndex_;
     }
@@ -287,22 +287,22 @@ enum class CacheResult
 
 // Holds the immutable guts of an AsmJSModule.
 //
 // AsmJSMetadata is built incrementally by ModuleValidator and then shared
 // immutably between AsmJSModules.
 
 struct AsmJSMetadataCacheablePod
 {
-    uint32_t                numFFIs;
-    uint32_t                srcLength;
-    uint32_t                srcLengthWithRightBrace;
-    bool                    usesSimd;
-
-    AsmJSMetadataCacheablePod() { PodZero(this); }
+    uint32_t                numFFIs = 0;
+    uint32_t                srcLength = 0;
+    uint32_t                srcLengthWithRightBrace = 0;
+    bool                    usesSimd = false;
+
+    AsmJSMetadataCacheablePod() = default;
 };
 
 struct js::AsmJSMetadata : Metadata, AsmJSMetadataCacheablePod
 {
     AsmJSGlobalVector       asmJSGlobals;
     AsmJSImportVector       asmJSImports;
     AsmJSExportVector       asmJSExports;
     CacheableCharsVector    asmJSFuncNames;