[clang] fix missing initialization msan failure

fixes msan failure reported here: https://lab.llvm.org/buildbot/#/builders/94/builds/5821/steps/17/logs/stdio

This was a regression introduced here: llvm#133610

Author: mizvekov

clang/lib/Sema/SemaCXXScopeSpec.cpp

@@ -873,6 +873,7 @@ bool Sema::ActOnCXXNestedNameSpecifier(Scope *S,
     DependentTemplateSpecializationTypeLoc SpecTL
       = Builder.push<DependentTemplateSpecializationTypeLoc>(T);
     SpecTL.setElaboratedKeywordLoc(SourceLocation());
+    SpecTL.setQualifierLoc(NestedNameSpecifierLoc());
     SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
     SpecTL.setTemplateNameLoc(TemplateNameLoc);
     SpecTL.setLAngleLoc(LAngleLoc);