remove more copyright headers

[matthiaskrgr]

r? @Mark-Simulacrum

[Centril]

@bors r+ rollup

[bors]

📌 Commit 8d727b2 has been approved by Centril

[bors]

⌛ Testing commit 8d727b2 with merge 074b085600d27fa29c87bfeb553482b68468596e...

[bors]

💔 Test failed - status-travis

[rust-highfive]

The job arm-android of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

[01:39:09] test string::test_str_clear ... ok
[01:39:09] test string::test_str_truncate_invalid_len ... ok
[01:39:09] test string::test_str_truncate ... ok
[01:39:09] test string::test_str_truncate_split_codepoint ... ok
[01:39:10] died due to signal 11
[01:39:10] 
[01:39:10] 
[01:39:10] 
[01:39:10] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "test" "--target" "arm-linux-androideabi" "-j" "4" "--release" "--locked" "--color" "always" "--features" "panic-unwind backtrace" "--manifest-path" "/checkout/src/libstd/Cargo.toml" "-p" "alloc" "--"
[01:39:10] 
[01:39:10] 
[01:39:10] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test --target arm-linux-androideabi
[01:39:10] Build completed unsuccessfully in 1:28:55
---
travis_time:end:0cb47c3b:start=1546211899798124935,finish=1546211899813716889,duration=15591954
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:19f3d934
$ ln -s . checkout && for CORE in obj/cores/core.*; do EXE=$(echo $CORE | sed 's|obj/cores/core\.[0-9]*\.!checkout!\(.*\)|\1|;y|!|/|'); if [ -f "$EXE" ]; then printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" "$CORE"; gdb --batch -q -c "$CORE" "$EXE" -iex 'set auto-load off' -iex 'dir src/' -iex 'set sysroot .' -ex bt -ex q; echo travis_fold":"end:crashlog; fi; done || true
travis_fold:end:after_failure.4
travis_fold:start:after_failure.5
travis_time:start:10506300
travis_time:start:10506300
$ cat ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers || true
cat: ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers: No such file or directory
travis_fold:end:after_failure.5
travis_fold:start:after_failure.6
travis_time:start:1d5838c4
$ dmesg | grep -i kill

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[Mark-Simulacrum]

@bors retry - #55861

[bors]

⌛ Testing commit 8d727b2 with merge 0432798...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: Centril
Pushing 0432798 to master...