Added set_break and clear_break for SerialPort

Windows and POSIX systems expose a similar API for setting and
clearing a break condition. This exposes it through the cross-
platform SerialPort trait.
38 jobs for xplatform_breaks in 6 minutes and 30 seconds (queued for 23 minutes and 37 seconds)
latest
Status Job ID Name Coverage
  Build
failed #552693905
aarch64-linux-android

00:01:20

passed #552693862
aarch64-unknown-linux-gnu

00:01:35

passed #552693923
aarch64-unknown-linux-musl

00:01:27

failed #552693907
arm-linux-androideabi

00:01:26

passed #552693864
arm-unknown-linux-gnueabi

00:01:32

passed #552693867
arm-unknown-linux-gnueabihf

00:01:34

passed #552693917
arm-unknown-linux-musleabi

00:01:29

passed #552693868
armv5te-unknown-linux-gnueabi

00:01:32

passed #552693918
armv5te-unknown-linux-musleabi

00:01:30

failed #552693908
armv7-linux-androideabi

00:01:29

passed #552693870
armv7-unknown-linux-gnueabihf

00:01:32

passed #552693921
armv7-unknown-linux-musleabihf

00:01:37

passed #552693874
i586-unknown-linux-gnu

00:01:32

passed #552693926
i586-unknown-linux-musl

00:01:52

failed #552693909
i686-linux-android

00:01:21

passed #552693913
i686-unknown-freebsd

00:01:25

passed #552693876
i686-unknown-linux-gnu

00:01:28

passed #552693933
i686-unknown-linux-musl

00:01:55

passed #552693878
mips-unknown-linux-gnu

00:01:32

passed #552693928
mips-unknown-linux-musl

00:01:25

passed #552693881
mips64-unknown-linux-gnuabi64

00:01:30

passed #552693891
mips64el-unknown-linux-gnuabi64

00:01:39

passed #552693894
mipsel-unknown-linux-gnu

00:01:32

passed #552693931
mipsel-unknown-linux-musl

00:01:37

passed #552693895
powerpc-unknown-linux-gnu

00:01:28

passed #552693897
powerpc64-unknown-linux-gnu

00:01:39

passed #552693898
powerpc64le-unknown-linux-gnu

00:01:34

passed #552693900
s390x-unknown-linux-gnu

00:01:42

passed #552693902
sparc64-unknown-linux-gnu

00:01:29

failed #552693911
x86_64-linux-android

00:01:28

passed #552693914
x86_64-unknown-freebsd

00:01:28

passed #552693904
x86_64-unknown-linux-gnu

00:02:01

passed #552693860
x86_64-unknown-linux-gnu-1.36.0

00:02:22

passed #552693934
x86_64-unknown-linux-musl

00:02:06

passed #552693916
x86_64-unknown-netbsd

00:01:27

 
  Lint
skipped #552693939
clippy
skipped #552693936
rustfmt
 
  External
passed continuous-integration/appveyor/branch

 
Name Stage Failure
failed
armv7-linux-androideabi Build
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0425`.
error: could not compile `serialport`.

To learn more, run the command again with --verbose.
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1
failed
x86_64-linux-android Build
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0425`.
error: could not compile `serialport`.

To learn more, run the command again with --verbose.
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1
failed
arm-linux-androideabi Build
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0425`.
error: could not compile `serialport`.

To learn more, run the command again with --verbose.
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1
failed
i686-linux-android Build
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0425`.
error: could not compile `serialport`.

To learn more, run the command again with --verbose.
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1
failed
aarch64-linux-android Build
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0425`.
error: could not compile `serialport`.

To learn more, run the command again with --verbose.
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1