store full definition AST for consts, fix noRewrite (#20115)

* continue #9582 for consts, close #9331, fix #20114

also move extractPragma to ast to pave the way for things like {.strdefine: "abc".} etc

* changelog correctly

* fix jsgen

* update tgetimpl

* fix sighashes

* fix #19766, add comment about postfix

* fix noRewrite LOL

refs #16620

* fix changelog

* fix destructors

tests/deprecated/tconst.nim

@@ -0,0 +1,8 @@
+discard """
+  nimout: '''
+tconst.nim(8, 9) Warning: abcd; foo is deprecated [Deprecated]
+'''
+"""
+
+const foo* {.deprecated: "abcd".} = 42
+discard foo

tests/macros/t19766_20114.nim

@@ -0,0 +1,16 @@
+discard """
+  action: compile
+  nimout: '''
+const
+  foo {.strdefine.} = "abc"
+let hey {.tddd.} = 5
+'''
+"""
+
+import macros
+
+template tddd {.pragma.}
+
+expandMacros:
+  const foo {.strdefine.} = "abc"
+  let hey {.tddd.} = 5

tests/macros/tgetimpl.nim

@@ -1,5 +1,5 @@
 discard """
-  nimout: '''"muhaha"
+  nimout: '''foo = "muhaha"
 proc poo(x, y: int) =
   let y = x
   echo ["poo"]'''

tests/pragmas/tcustom_pragma.nim

@@ -439,3 +439,43 @@ when false:
 
   # left-to-right priority/override order for getCustomPragmaVal
   assert bb.getCustomPragmaVal(hehe) == (key: "hi", val: "hu", haha: "he")
+
+{.experimental: "dynamicBindSym".}
+
+# const
+block:
+  template myAttr() {.pragma.}
+  template myAttr2(x: int) {.pragma.}
+  template myAttr3(x: string) {.pragma.}
+
+  type
+    MyObj2 = ref object
+
+  const a {.myAttr,myAttr2(2),myAttr3:"test".}: int = 0
+  const b {.myAttr,myAttr2(2),myAttr3:"test".} = 0
+
+  macro forceHasCustomPragma(x: untyped, y: typed): untyped =
+    var x = bindSym(x.repr)
+    for c in x:
+      if c.symKind == nskConst:
+        x = c
+        break
+    result = getAst(hasCustomPragma(x, y))
+
+  macro forceGetCustomPragmaVal(x: untyped, y: typed): untyped =
+    var x = bindSym(x.repr)
+    for c in x:
+      if c.symKind == nskConst:
+        x = c
+        break
+    result = getAst(getCustomPragmaVal(x, y))
+
+  template check(s: untyped) =
+    doAssert forceHasCustomPragma(s, myAttr)
+    doAssert forceHasCustomPragma(s, myAttr2)
+    doAssert forceGetCustomPragmaVal(s, myAttr2) == 2
+    doAssert forceHasCustomPragma(s, myAttr3)
+    doAssert forceGetCustomPragmaVal(s, myAttr3) == "test"
+
+  check(a)
+  check(b)

tests/trmacros/tnorewrite.nim

@@ -0,0 +1,20 @@
+block:
+  proc get(x: int): int = x
+
+  template t{get(a)}(a: int): int =
+    {.noRewrite.}:
+      get(a) + 1
+
+  doAssert get(0) == 1
+
+block:
+  var x: int
+
+  template asgn{a = b}(a: int{lvalue}, b: int) =
+    let newVal = b + 1
+    # ^ this is needed but should it be?
+    {.noRewrite.}:
+      a = newVal
+
+  x = 10
+  doAssert x == 11, $x

tests/trmacros/trmacros_various.nim

@@ -33,7 +33,8 @@ block tcse:
 
 block hoist:
   template optPeg{peg(pattern)}(pattern: string{lit}): Peg =
-    var gl {.global, gensym.} = peg(pattern)
+    {.noRewrite.}:
+      var gl {.global, gensym.} = peg(pattern)
     gl
   doAssert match("(a b c)", peg"'(' @ ')'")
   doAssert match("W_HI_Le", peg"\y 'while'")