fixes #18235 - proc annotation type macro sym leak (#18249)

* fixes #18235 - proc annotation type macro sym leak

- also fixed a typo
- proc annotations guard symbol exports with shadow scopes
- symbol handling is shadow scope aware

* test for exporting an existing unexported sym

this one is for my homie alaviss.

* Special handling not needed in semProcAnnotation

* Testcasing

* [skip ci]  clean-up and add some more comments

* [skip ci] rm trailing whitespace

Co-authored-by: Clyybber <darkmine956@gmail.com>

tests/macros/m18235.nim

@@ -0,0 +1,42 @@
+import macros
+
+# Necessary code to update the AST on a symbol across module boundaries when
+# processed by a type macro. Used by a test of a corresponding name of this
+# file.
+
+macro eexport(n: typed): untyped =
+  result = copyNimTree(n)
+  # turn exported nnkSym -> nnkPostfix(*, nnkIdent), forcing re-sem
+  result[0] = nnkPostfix.newTree(ident"*").add:
+    n.name.strVal.ident
+
+macro unexport(n: typed): untyped =
+  result = copyNimTree(n)
+  # turn nnkSym -> nnkIdent, forcing re-sem and dropping any exported-ness
+  # that might be present
+  result[0] = n.name.strVal.ident
+
+proc foo*() {.unexport.} = discard
+proc bar() {.eexport.} = discard
+
+proc foooof*() {.unexport, eexport, unexport.} = discard
+proc barrab() {.eexport, unexport, eexport.} = discard
+
+macro eexportMulti(n: typed): untyped =
+  # use the call version of `eexport` macro for one or more decls
+  result = copyNimTree(n)
+  for i in 0..<result.len:
+    result[i] = newCall(ident"eexport", result[i])
+
+macro unexportMulti(n: typed): untyped =
+  # use the call version of `unexport` macro for one or more decls
+  result = copyNimTree(n)
+  for i in 0..<result.len:
+    result[i] = newCall(ident"unexport", result[i])
+
+unexportMulti:
+  proc oof*() = discard
+
+eexportMulti:
+  proc rab() = discard
+  proc baz*() = discard

tests/macros/t18235.nim

@@ -0,0 +1,18 @@
+import m18235
+
+# this must error out because it was never actually exported
+doAssert(not declared(foo))
+doAssert not compiles(foo())
+
+doAssert(not declared(foooof))
+doAssert not compiles(foooof())
+
+doAssert(not declared(oof))
+doAssert not compiles(oof())
+
+# this should have been exported just fine
+
+bar()
+barrab()
+rab()
+baz()