C23-compliant parser

[ForNeVeR]

Section 6 Language of the C standard includes a number of EBNF-like definitions Cesium should support.

• 6 Language
  • 6.4 Lexical elements: C23-compliant lexer #76
  • 6.5 Expressions: Parse all the C expressions #207
  • 6.6 Constant expressions
  • 6.7 Declarations: Parse all the C declarations #211
  • 6.8 Statements and blocks: Parse all the C statements #210
  • 6.9 External definitions
    • 6.9.1 Function definitions
    • 6.9.2 External object definitions
  • 6.10 Preprocessing directives: C23-compliant preprocessor #77