Minor: increase memory in JS backend tests.
Minor: drop obsolete code.
"js" -> "kotlin.js"
JS stdlib: test that js library doesn't contain internal declarations.
JS stdlib: fixed visibility in some declarations.
Minor in JS lib: dropped semicolon in package declarations.
Minor: drop semicolon in package declaration everywhere.
Minor: made noImpl generic to avoid using in wrong context.
Minor: "js.noImpl" -> "noImpl"