ClangImporter: support __isoc_va_list for WASI/musl

Author: MaxDesiatov

lib/ClangImporter/ImportType.cpp

@@ -787,7 +787,7 @@ 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.

test/Interop/C/va_list/Inputs/module.modulemap

@@ -0,0 +1,4 @@
+module ImportCVAList {
+  header "va_list.h"
+  export *
+}

test/Interop/C/va_list/Inputs/va_list.h

@@ -0,0 +1,10 @@
+#include <stdarg.h>
+
+typedef va_list __gnuc_va_list;
+typedef va_list __isoc_va_list;
+typedef va_list __va_list;
+
+va_list va;
+__gnuc_va_list gnu;
+__isoc_va_list isoC;
+__va_list underscore;

test/Interop/C/va_list/va_list.swift

@@ -0,0 +1,6 @@
+// RUN: %target-swift-ide-test -print-module -module-to-print=ImportCVAList -I %S/Inputs -source-filename=x | %FileCheck %s
+
+// CHECK: var va: CVaListPointer
+// CHECK: var gnu: CVaListPointer
+// CHECK: var isoC: CVaListPointer
+// CHECK: var underscore: CVaListPointer