Avoid evaluating macros twice in type sections (#10550)

Fixes #10548

compiler/semstmts.nim

@@ -1129,6 +1129,11 @@ proc typeSectionRightSidePass(c: PContext, n: PNode) =
         #debug s.typ
       s.ast = a
       popOwner(c)
+      # If the right hand side expression was a macro call we replace it with
+      # its evaluated result here so that we don't execute it once again in the
+      # final pass
+      if a[2].kind in nkCallKinds:
+        a[2] = newNodeIT(nkType, a[2].info, t)
     if sfExportc in s.flags and s.typ.kind == tyAlias:
       localError(c.config, name.info, "{.exportc.} not allowed for type aliases")
     let aa = a.sons[2]

tests/macros/tmacrotypes.nim

@@ -23,3 +23,18 @@ checkType(voidProc(), "void")
 checkType(intProc(10, 20.0), "int")
 checkType(voidProc, "procTy")
 checkProcType(voidProc)
+
+# bug #10548
+block:
+  var c {.compileTime.} = 0
+
+  macro meshImpl(arg: typed): untyped =
+    inc c
+    result = arg
+
+  type
+    Blub = int32
+    Mesh = meshImpl(Club)
+    Club = Blub
+
+  static: doAssert(c == 1)