mk: tests.mk simplify the method to clean arm testing directory
etc: modify adb_run_wrapper.sh to avoid 'expr' unrecognization at some android devices
etc: add TEST_EXEC_ENV for run-pass to adb_run_wrapper.sh
test: adjust some test cases of run-pass for android
std: fix stat struct of android (SEGV error from run-pass/stat.rs on android)
Turn off jemalloc
test: xfail bench/task-perf-one-million. OOM on 32-bit linux w/o opts
replace #[inline(always)] with #[inline]. r=burningtree.
xfail std::num::complex::test_norm on x86, r=burningtree.
rusti: disable tests on 32bit mac. r=burningtree.
std: Work around some failing 'run' tests when valgrinding. #7224

Under valgrind on 64->32 cross compiles the dynamic linker is emitting
some error messages on stderr, which interferes with the tests that
are checking stderr.
rusti: Disable tests on macos harder
std::rt: Work around a dynamic borrowck bug
rustc: Dispose of LLVM passes in test cases
libsyntax: Remove `drop` as a keyword.
Fix update snapshot script for rename
Ignore rustpkg tests
core -> extra for mac
xfail box-related debug-info tests r=snapshot
ignore inherited environment test under valgrind r=snapshot