Revert "Fix Clang-tidy modernize-deprecated-headers warnings in remaining files; other minor fixes."

This reverts commit r265454 since it broke the build.  E.g.:

  http://lab.llvm.org:8080/green/job/clang-stage1-cmake-RA-incremental_build/22413/

llvm-svn: 265459
diff --git a/llvm/lib/Support/SearchForAddressOfSpecialSymbol.cpp b/llvm/lib/Support/SearchForAddressOfSpecialSymbol.cpp
index 711760b..55f3320 100644
--- a/llvm/lib/Support/SearchForAddressOfSpecialSymbol.cpp
+++ b/llvm/lib/Support/SearchForAddressOfSpecialSymbol.cpp
@@ -14,12 +14,10 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include <cstring>
-
-namespace {
+#include <string.h>
 
 // Must declare the symbols in the global namespace.
-void *DoSearch(const char* symbolName) {
+static void *DoSearch(const char* symbolName) {
 #define EXPLICIT_SYMBOL(SYM) \
    extern void *SYM; if (!strcmp(symbolName, #SYM)) return &SYM
 
@@ -53,12 +51,8 @@
   return nullptr;
 }
 
-} // end anonymous namespace
-
 namespace llvm {
-
 void *SearchForAddressOfSpecialSymbol(const char* symbolName) {
   return DoSearch(symbolName);
 }
-
-} // end namespace llvm
+}  // namespace llvm