[clang-tools-extra] [libc] Refactor scanf reader to match printf (PR #66023)

[Siva Chandra via cfe-commits]

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@@ -9,15 +9,57 @@
 #ifndef LLVM_LIBC_SRC_STDIO_SCANF_CORE_VFSCANF_INTERNAL_H
 #define LLVM_LIBC_SRC_STDIO_SCANF_CORE_VFSCANF_INTERNAL_H
 
+#include "src/__support/File/file.h"
 #include "src/__support/arg_list.h"
+#include "src/stdio/scanf_core/reader.h"
+#include "src/stdio/scanf_core/scanf_main.h"
 
 #include <stdio.h>
 
 namespace __llvm_libc {
+
+namespace internal {
+#ifndef LIBC_COPT_SCANF_USE_SYSTEM_FILE
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sivachandra wrote:

Nit: Add a line before and after.

https://github.com/llvm/llvm-project/pull/66023