emcc logging improvements
fix the case where emcc's input and output is a bitcode file
Fix test runner banned engine filtering for SPIDERMONKEY_ENGINE when cmdline params are automatically added to that engine.
Merge pull request #2262 from juj/fix_js_engine_filtering

Fix test runner banned engine filtering for SPIDERMONKEY_ENGINE.
add EM_ASM_ARGS, a nicer name for EM_ASM_
better error handling in EM_ASM
update test_idbfs_sync to use EM_ASM with input arguments, which is more idiomatic
add testing for EM_ASM_ARGS
comment
Merge remote-tracking branch 'upstream/incoming' into incoming