fix #15005; [ARC] Global variable declared in a block is destroyed too… (#22388)

* fix #15005 [ARC] Global variable declared in a block is destroyed too early

compiler/injectdestructors.nim

@@ -1153,7 +1153,8 @@ proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope, flags: set[MoveOrCopy
         let snk = c.genSink(s, dest, ri, flags)
         result = newTree(nkStmtList, snk, c.genWasMoved(ri))
       elif ri.sym.kind != skParam and ri.sym.owner == c.owner and
-          isLastRead(ri, c, s) and canBeMoved(c, dest.typ) and not isCursor(ri):
+          isLastRead(ri, c, s) and canBeMoved(c, dest.typ) and not isCursor(ri) and
+          {sfGlobal, sfPure} <= ri.sym.flags == false:
         # Rule 3: `=sink`(x, z); wasMoved(z)
         let snk = c.genSink(s, dest, ri, flags)
         result = newTree(nkStmtList, snk, c.genWasMoved(ri))

tests/global/t15005.nim

@@ -0,0 +1,18 @@
+type
+  T = ref object
+    data: string
+
+template foo(): T =
+  var a15005 {.global.}: T
+  once:
+    a15005 = T(data: "hi")
+
+  a15005
+
+proc test() =
+  var b15005 = foo()
+
+  doAssert b15005.data == "hi"
+
+test()
+test()