[gn build] Port 6a9487df

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

@@ -55,6 +55,7 @@ static_library("bugprone") {
     "StringConstructorCheck.cpp",
     "StringIntegerAssignmentCheck.cpp",
     "StringLiteralWithEmbeddedNulCheck.cpp",
+    "StringviewNullptrCheck.cpp",
     "SuspiciousEnumUsageCheck.cpp",
     "SuspiciousIncludeCheck.cpp",
     "SuspiciousMemoryComparisonCheck.cpp",