[FFI] Make binaryninjacore.h parseable with default xcode clang

[bloombit-dev]

This pull request makes binaryninjacore.h parseable with default MacOS clang compiler.

binaryninjacore.h does not parse with default arguments under clang packaged from Xcode with the following versions:

Xcode 26.4.1, Build version 17E202
Apple clang version 21.0.0 (clang-2100.0.123.102).

bloombit@Mac binaryninja-api % clang -fsyntax-only binaryninjacore.h
binaryninjacore.h:827:3: error: must use 'enum' tag to refer to type 'BNFunctionGraphType'
  827 |                 BNFunctionGraphType type;
      |                 ^
      |                 enum
binaryninjacore.h:1188:3: error: must use 'enum' tag to refer to type 'BNInlineDuringAnalysis'
 1188 |                 BNInlineDuringAnalysis value;
      |                 ^
      |                 enum
...
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.

[CLAassistant]

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