Switch from static_cast<> to cast<>, update identifier for coding conventions; NFC.

llvm-svn: 349955
diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index cc3c25c..47130cf 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -469,11 +469,9 @@
 }
 
 /// ActOnCaseStmtBody - This installs a statement as the body of a case.
-void Sema::ActOnCaseStmtBody(Stmt *caseStmt, Stmt *SubStmt) {
+void Sema::ActOnCaseStmtBody(Stmt *S, Stmt *SubStmt) {
   DiagnoseUnusedExprResult(SubStmt);
-
-  auto *CS = static_cast<CaseStmt *>(caseStmt);
-  CS->setSubStmt(SubStmt);
+  cast<CaseStmt>(S)->setSubStmt(SubStmt);
 }
 
 StmtResult