Port: Allow the public header to work in C++ mode.

Without this, includes of the header must be wrapped in extern "C",
which then causes problems if the config header includes headers that
expect to be included in C or C++ mode.

Signed-off-by: willieyz <willie.zhao@chelpis.com>

Author: willieyz

.clang-format

@@ -19,6 +19,7 @@ IncludeBlocks: Preserve
 # as "attributes" so they don't get increasingly indented line after line
 BreakBeforeBraces: Allman
 InsertBraces: true
+IndentExternBlock: NoIndent
 WhitespaceSensitiveMacros: ['__contract__', '__loop__' ]
 Macros:
  # Make this artifically long to avoid function bodies after short contracts

mldsa/mldsa_native.h

@@ -199,6 +199,12 @@
 #include <stddef.h>
 #include <stdint.h>
 
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
 /*************************************************
  * Name:        crypto_sign_keypair_internal
  *
@@ -845,6 +851,10 @@ int MLD_API_NAMESPACE(pk_from_sk)(
 #endif
 );
 
+#ifdef __cplusplus
+}
+#endif
+
 /****************************** SUPERCOP API *********************************/
 
 #if !defined(MLD_CONFIG_API_NO_SUPERCOP)