strict effects (#18777)

* fixes #17369
* megatest is green for --cpu:arm64
* docgen output includes more tags/raises
* implemented 'effectsOf' 
* algorithm.nim: uses new effectsOf annotation
* closes #18376
* closes #17475
* closes #13905
* allow effectsOf: [a, b]
* added a test case
* parameters that are not ours cannot be declared as .effectsOf
* documentation
* manual: added the 'sort' example
* bootstrap with the new better options

compiler/semstmts.nim

@@ -1953,6 +1953,10 @@ proc semProcAux(c: PContext, n: PNode, kind: TSymKind,
   if not hasProto:
     implicitPragmas(c, s, n.info, validPragmas)
 
+  if n[pragmasPos].kind != nkEmpty:
+    setEffectsForProcType(c.graph, s.typ, n[pragmasPos], s)
+  s.typ.flags.incl tfEffectSystemWorkaround
+
   # To ease macro generation that produce forwarded .async procs we now
   # allow a bit redundancy in the pragma declarations. The rule is
   # a prototype's pragma list must be a superset of the current pragma
@@ -2211,8 +2215,9 @@ proc evalInclude(c: PContext, n: PNode): PNode =
       incMod(c, n, it, result)
 
 proc setLine(n: PNode, info: TLineInfo) =
-  for i in 0..<n.safeLen: setLine(n[i], info)
-  n.info = info
+  if n != nil:
+    for i in 0..<n.safeLen: setLine(n[i], info)
+    n.info = info
 
 proc semPragmaBlock(c: PContext, n: PNode): PNode =
   checkSonsLen(n, 2, c.config)