[WASM] Fix test/stdlib/VarArgs.swift

Author: kateinoigakukun

lib/ClangImporter/ImportType.cpp

@@ -711,7 +711,7 @@ namespace {
         }
 
         static const llvm::StringLiteral vaListNames[] = {
-          "va_list", "__gnuc_va_list", "__va_list"
+          "va_list", "__gnuc_va_list", "__isoc_va_list", "__va_list"
         };
 
         ImportHint hint = ImportHint::None;

lib/ClangImporter/MappedTypes.def

@@ -128,6 +128,7 @@ MAP_STDLIB_TYPE("u_int64_t", UnsignedInt, 64, "UInt64", false, DoNothing)
 // There's an explicit workaround in ImportType.cpp's VisitDecayedType for that.
 MAP_STDLIB_TYPE("va_list", VaList, 0, "CVaListPointer", false, DoNothing)
 MAP_STDLIB_TYPE("__gnuc_va_list", VaList, 0, "CVaListPointer", false, DoNothing)
+MAP_STDLIB_TYPE("__isoc_va_list", VaList, 0, "CVaListPointer", false, DoNothing)
 MAP_STDLIB_TYPE("__va_list", VaList, 0, "CVaListPointer", false, DoNothing)
 
 // libkern/OSTypes.h types.

stdlib/public/core/VarArgs.swift

@@ -565,7 +565,7 @@ final internal class __VaListBuilder {
     // supported vararg type is greater than the alignment of Int, such
     // as non-iOS ARM. Note that we can't use alignof because it
     // differs from ABI alignment on some architectures.
-#if arch(arm) && !os(iOS)
+#if (arch(arm) && !os(iOS)) || arch(wasm32)
     if let arg = arg as? _CVarArgAligned {
       let alignmentInWords = arg._cVarArgAlignment / MemoryLayout<Int>.size
       let misalignmentInWords = count % alignmentInWords