Revert "Revert "Revert "Turn off extern templates for most uses."""

This reverts commit 75746a3228.

Bug: 72411393
Test: normal build, and build with clang 7.0 in system/core/demangle
Change-Id: I6c67b5210e131600ad9706afd2e1cbd7f7f40237

include/__config

@@ -905,7 +905,7 @@ template <unsigned> struct __static_assert_check {};
 #endif
 
 #ifndef _LIBCPP_EXTERN_TEMPLATE
-#define _LIBCPP_EXTERN_TEMPLATE(...)
+#define _LIBCPP_EXTERN_TEMPLATE(...) extern template __VA_ARGS__;
 #endif
 
 #ifndef _LIBCPP_EXTERN_TEMPLATE2

src/algorithm.cpp

@@ -7,8 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#undef _LIBCPP_EXTERN_TEMPLATE
-#define _LIBCPP_EXTERN_TEMPLATE(...) extern template __VA_ARGS__;
 #include "algorithm"
 #include "random"
 #include "mutex"

src/ios.cpp

@@ -9,9 +9,6 @@
 
 #include "__config"
 
-#undef _LIBCPP_EXTERN_TEMPLATE
-#define _LIBCPP_EXTERN_TEMPLATE(...) extern template __VA_ARGS__;
-
 #include "ios"
 
 #include <stdlib.h>

src/locale.cpp

@@ -7,9 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#undef _LIBCPP_EXTERN_TEMPLATE
-#define _LIBCPP_EXTERN_TEMPLATE(...) extern template __VA_ARGS__;
-
 // On Solaris, we need to define something to make the C99 parts of localeconv
 // visible.
 #ifdef __sun__

src/string.cpp

@@ -7,9 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#undef _LIBCPP_EXTERN_TEMPLATE
-#define _LIBCPP_EXTERN_TEMPLATE(...) extern template __VA_ARGS__;
-
 #include "string"
 #include "cstdlib"
 #include "cwchar"

src/valarray.cpp

@@ -7,9 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#undef _LIBCPP_EXTERN_TEMPLATE
-#define _LIBCPP_EXTERN_TEMPLATE(...) extern template __VA_ARGS__;
-
 #include "valarray"
 
 _LIBCPP_BEGIN_NAMESPACE_STD