sh: Don't modify exit status when break/continue/return passes !.

This matches what would happen if  ! P  were to be replaced with
if P; then false; else true; fi.

Example:
  f() { ! return 0; }; f

2 files changed, 10 insertions, 0 deletions

diff --git a/tools/regression/bin/sh/execution/not1.0 b/tools/regression/bin/sh/execution/not1.0
new file mode 100644
index 0000000..12c6265
--- /dev/null
+++ b/tools/regression/bin/sh/execution/not1.0
@@ -0,0 +1,4 @@
+# $FreeBSD$
+
+f() { ! return $1; }
+f 0 && ! f 1
diff --git a/tools/regression/bin/sh/execution/not2.0 b/tools/regression/bin/sh/execution/not2.0
new file mode 100644
index 0000000..1b128d0
--- /dev/null
+++ b/tools/regression/bin/sh/execution/not2.0
@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+while :; do
+	! break
+	exit 3
+done