[clang] [clang][coverage] fixing "if constexpr" and "if consteval" coverage report (PR #77214)

[via cfe-commits]

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@@ -1631,8 +1631,10 @@ class CompoundStmt final
                               SourceLocation RB);
 
   // Build an empty compound statement with a location.
-  explicit CompoundStmt(SourceLocation Loc)
-      : Stmt(CompoundStmtClass), LBraceLoc(Loc), RBraceLoc(Loc) {
+  explicit CompoundStmt(SourceLocation Loc) : CompoundStmt(Loc, Loc) {}
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cor3ntin wrote:

That does not seem to be used

https://github.com/llvm/llvm-project/pull/77214