[clang] [clang-tools-extra] [libcxx] [lldb] [Clang] Make the SizeType, SignedSizeType and PtrdiffType be named sugar types instead of built-in types (PR #143653)

[Erich Keane via cfe-commits]

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@@ -320,6 +320,92 @@ bool clang::analyze_format_string::ParseUTF8InvalidSpecifier(
 // Methods on ArgType.
 //===----------------------------------------------------------------------===//
 
+static bool namedTypeToLengthModifierKind(ASTContext &Ctx, QualType QT,
+                                          LengthModifier::Kind &K) {
+  for (/**/; const auto *TT = QT->getAs<TypedefType>();
+       QT = TT->getDecl()->getUnderlyingType()) {
+    const auto *TD = TT->getDecl();
+    const auto *DC = TT->getDecl()->getDeclContext();
+    bool RC = false;
+    if (Ctx.getLangOpts().C99) {
+      RC = DC->isTranslationUnit();
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erichkeane wrote:

>previous review feedback suggesting that isStdNamespace should be avoided in C mode
Curious on the reasoning here... I don't think it is problematic? 

https://github.com/llvm/llvm-project/pull/143653