Constructor declaration AST node.
EBNF grammar:
constructor-declaration:
(attributes)? (constructor-modifiers)? constructor-declarator constructor-body
constructor-modifiers:
(constructor-modifier)+
constructor-modifier:
"public"
"protected"
"internal"
"private"
"extern"
constructor-declarator:
identifier "(" (formal-parameter-list)? ")" (constructor-initializer)?
constructor-initializer:
":" base "(" (argument-list)? ")"
":" this "(" (argument-list)? ")"
constructor-body:
block
";"