noSideEffect has no effect in term rewriting macro

[bobeff]

According to the documentation, the following code should not match the term rewriting macro.

template optMul{`*`(a, 2)}(a: int{noSideEffect}): int = a+a

proc f(): int =
  echo "side effect!"
  result = 55

echo f() * 2 # not optimized ;-)

Current Output

side effect!
side effect!
110

Expected Output

side effect!
110

Compiler Version

$ nim -v
Nim Compiler Version 1.5.1 [Linux: amd64]
Compiled at 2021-01-03
Copyright (c) 2006-2020 by Andreas Rumpf

git hash: 2aed4186989e0c9192eadcc28f989d41f92237b0
active boot switches: -d:danger

[awr1]

Regression from v0.14.2 to v0.15

[ringabout]

duplicated issue:
see #6217