move system.dollars in a separate file (#10829)

tests/assert/tfailedassert_stacktrace.nim

@@ -6,7 +6,7 @@ const expected = """
 tfailedassert_stacktrace.nim(34) tfailedassert_stacktrace
 tfailedassert_stacktrace.nim(33) foo
 assertions.nim(*)       failedAssertImpl
-assertions.nim(*)        raiseAssert
+assertions.nim(*)       raiseAssert
 fatal.nim(*)            sysFatal"""
 
 proc tmatch(x, p: string): bool =

tests/metatype/ttypetraits2.nim

@@ -1,7 +1,5 @@
 # todo: merge with $nimc_D/tests/metatype/ttypetraits.nim (currently disabled)
 
-from typetraits import `$` # checks fix for https://github.com/c-blake/cligen/issues/84
-
 import typetraits
 
 block: # isNamedTuple