[gn build] Port 42179bb

Author: llvmgnsyncbot

llvm/utils/gn/secondary/clang-tools-extra/clang-tidy/bugprone/BUILD.gn

@@ -73,6 +73,7 @@ static_library("bugprone") {
     "SuspiciousSemicolonCheck.cpp",
     "SuspiciousStringCompareCheck.cpp",
     "SwappedArgumentsCheck.cpp",
+    "SwitchMissingDefaultCaseCheck.cpp",
     "TerminatingContinueCheck.cpp",
     "ThrowKeywordMissingCheck.cpp",
     "TooSmallLoopVariableCheck.cpp",