rename fillins/base64.c to handle gn being special

Change-Id: I368e98f7484bdafac8d8600a6b4d5d7013e08817
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/62705
Auto-Submit: Bob Beck <bbe@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Bob Beck <bbe@google.com>
Reviewed-by: David Benjamin <davidben@google.com>

pki/fillins/fillins_base64.cc

@@ -4,7 +4,7 @@
 
 #include <openssl/base64.h>
 
-#include "base64.h"
+#include "fillins_base64.h"
 
 #include <vector>
 

pki/import_spec.json

@@ -82,7 +82,7 @@
     {"match": "^#include \"base/memory/ref_counted.h\"",
      "replace": "#include <memory>"},
     {"match": "^#include \"base/base64.h\"",
-     "replace": "#include \"fillins/base64.h\""},
+     "replace": "#include \"fillins/fillins_base64.h\""},
     {"match": "^#include \"base/strings/stringprintf.h\"",
      "replace": ""},
     {"match": "^#include \"third_party/boringssl/src/include/openssl/(.*).h\"",

pki/pem.cc

@@ -5,7 +5,7 @@
 #include "string_util.h"
 #include "pem.h"
 
-#include "fillins/base64.h"
+#include "fillins/fillins_base64.h"
 #include <string_view>
 
 #include "fillins/string_util.h"

sources.cmake

@@ -353,7 +353,7 @@ set(
   pki/crl.cc
   pki/encode_values.cc
   pki/extended_key_usage.cc
-  pki/fillins/base64.cc
+  pki/fillins/fillins_base64.cc
   pki/fillins/ip_address.cc
   pki/fillins/openssl_util.cc
   pki/fillins/string_util.cc