[clang] [clang-tools-extra] [clang] Add a valid begin source location for abbreviated function templates (PR #174723)

[Younan Zhang via cfe-commits]

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@@ -235,10 +235,10 @@ getGenericLambdaTemplateParameterList(LambdaScopeInfo *LSI, Sema &SemaRef) {
   if (!LSI->GLTemplateParameterList && !LSI->TemplateParams.empty()) {
     LSI->GLTemplateParameterList = TemplateParameterList::Create(
         SemaRef.Context,
-        /*Template kw loc*/ SourceLocation(),
+        /*Template kw loc*/ LSI->IntroducerRange.getBegin(),
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zyn0217 wrote:

Let's have a brief comment here explaining the purpose of this location.

https://github.com/llvm/llvm-project/pull/174723