Allow macrocall in function def syntax

Goes with JuliaLang/julia#55040

Author: Keno

src/parser.jl

@@ -2102,6 +2102,10 @@ function parse_function_signature(ps::ParseState, is_function::Bool)
         if peek(ps) != K"("
             # function f() end  ==> (function (call f))
             parse_unary_prefix(ps)
+            if peek_behind(ps).kind == K"macrocall"
+                min_supported_version(v"1.12", ps, mark, "macrocall function sig")
+                needs_parse_call = false
+            end
         else
             # When an initial parenthesis is present, we need to distinguish
             # between