Remove files with API leak

This removes non-starboardized files from the build with cobalt
toolchain.

b/150410605

third_party/boringssl/BUILD.generated.gni

@@ -40,14 +40,11 @@ crypto_sources = [
   "src/crypto/base64/base64.c",
   "src/crypto/bio/bio.c",
   "src/crypto/bio/bio_mem.c",
-  "src/crypto/bio/connect.c",
-  "src/crypto/bio/fd.c",
   "src/crypto/bio/file.c",
   "src/crypto/bio/hexdump.c",
   "src/crypto/bio/internal.h",
   "src/crypto/bio/pair.c",
   "src/crypto/bio/printf.c",
-  "src/crypto/bio/socket.c",
   "src/crypto/bio/socket_helper.c",
   "src/crypto/bn_extra/bn_asn1.c",
   "src/crypto/bn_extra/convert.c",
@@ -267,6 +264,14 @@ crypto_sources = [
   "src/third_party/fiat/internal.h",
 ]
 
+if (is_native_target_build) {
+crypto_sources += [
+  "src/crypto/bio/connect.c",
+  "src/crypto/bio/fd.c",
+  "src/crypto/bio/socket.c",
+]
+}
+
 crypto_headers = [
   "src/include/openssl/aead.h",
   "src/include/openssl/aes.h",