Allow GlobalRef and module qualified names in macro definitions (#53535)

The following is currently an error:
```
julia> module MyMacroModule
           macro mymacro end
       end
Main.MyMacroModule

julia> macro MyMacroModule.mymacro()
           1
       end
ERROR: syntax: invalid macro definition around REPL[2]:1
Stacktrace:
 [1] top-level scope
   @ REPL[2]:1
```

Discussing with Jeff, we didn't think there was any good reason not to
allow this, just a missing case in lowering. It's probably not
particularly useful (unlike the corresponding case for functions that is
used all the time), but it came up in writing a test case for #53515.

Author: Keno

src/julia-parser.scm

@@ -2610,15 +2610,23 @@
 
 (define (valid-modref? e)
   (and (length= e 3) (eq? (car e) '|.|) (pair? (caddr e))
-       (eq? (car (caddr e)) 'quote) (symbol? (cadr (caddr e)))
+       (or (eq? (car (caddr e)) 'quote)
+           (eq? (car (caddr e)) 'inert))
+       (symbol? (cadr (caddr e)))
        (or (symbol? (cadr e))
            (valid-modref? (cadr e)))))
 
 (define (macroify-name e . suffixes)
   (cond ((symbol? e) (symbol (apply string #\@ e suffixes)))
+        ((and (pair? e) (eq? (car e) 'quote))
+         `(quote ,(apply macroify-name (cadr e) suffixes)))
+        ((and (pair? e) (eq? (car e) 'inert))
+         `(inert ,(apply macroify-name (cadr e) suffixes)))
+        ((globalref? e)
+         `(globalref ,(cadr e) ,(apply macroify-name (caddr e) suffixes)))
         ((valid-modref? e)
          `(|.| ,(cadr e)
-               (quote ,(apply macroify-name (cadr (caddr e)) suffixes))))
+               ,(apply macroify-name (caddr e) suffixes)))
         (else (error (string "invalid macro usage \"@(" (deparse e) ")\"" )))))
 
 (define (macroify-call s call startloc)

src/julia-syntax.scm

@@ -1347,15 +1347,18 @@
                (else (error "invalid let syntax"))))
              (else (error "invalid let syntax")))))))))
 
+(define (valid-macro-def-name? e)
+  (or (symbol? e) (valid-modref? e) (globalref? e)))
+
 (define (expand-macro-def e)
   (cond ((and (pair? (cadr e))
               (eq? (car (cadr e)) 'call)
-              (symbol? (cadr (cadr e))))
+              (valid-macro-def-name? (cadr (cadr e))))
          (let ((anames (remove-empty-parameters (cddr (cadr e)))))
            (if (has-parameters? anames)
                (error "macros cannot accept keyword arguments"))
            (expand-forms
-            `(function (call ,(symbol (string #\@ (cadr (cadr e))))
+            `(function (call ,(macroify-name (cadr (cadr e)))
                              (|::| __source__ (core LineNumberNode))
                              (|::| __module__ (core Module))
                              ,@(map (lambda (v)
@@ -1364,8 +1367,8 @@
                                           v))
                                     anames))
                        ,@(cddr e)))))
-        ((and (length= e 2) (symbol? (cadr e)))
-         (expand-forms `(function ,(symbol (string #\@ (cadr e))))))
+        ((and (length= e 2) (valid-macro-def-name? (cadr e)))
+         (expand-forms `(function ,(macroify-name (cadr e)))))
         (else
          (error "invalid macro definition"))))
 

test/syntax.jl

@@ -3637,3 +3637,16 @@ end
     @test array == [7]
     @test execs == 4
 end
+
+# Allow GlobalRefs in macro definition
+module MyMacroModule
+    macro mymacro end
+end
+macro MyMacroModule.mymacro()
+    1
+end
+@eval macro $(GlobalRef(MyMacroModule, :mymacro))(x)
+    2
+end
+@test (@MyMacroModule.mymacro) == 1
+@test (@MyMacroModule.mymacro(a)) == 2