fix #17325 linux 32bit CI; fix #17085 flaky test (#17469)

tests/gc/trace_globals.nim

@@ -1,11 +1,20 @@
 discard """
-  output: '''10000000
+  output: '''
+10000000
 10000000
 10000000'''
 """
 
 # bug #17085
 
+#[
+refs https://github.com/nim-lang/Nim/issues/17085#issuecomment-786466595
+with --gc:boehm, this warning sometimes gets generated:
+Warning: Repeated allocation of very large block (appr. size 14880768):
+May lead to memory leak and poor performance.
+nim CI now runs this test with `testWithoutBoehm` to avoid running it with --gc:boehm.
+]#
+
 proc init(): string =
   for a in 0..<10000000:
     result.add 'c'
@@ -16,6 +25,8 @@ proc f() =
   var c {.global.} = init()
 
   echo a.len
+    # `echo` intentional according to
+    # https://github.com/nim-lang/Nim/pull/17469/files/0c9e94cb6b9ebca9da7cb19a063fba7aa409748e#r600016573
   echo b.len
   echo c.len