js-on-sx: baseline commit (278/280 unit, 148/148 slice, runner stub)

Initial commit of the lib/js/ tree and plans/ directory. A previous
session left template-string work in progress — 278/280 unit tests pass
(2 failing: tpl part-count off-by-one, escaped-backtick ident lookup).
test262-runner.py and scoreboard are placeholders (0/8 with 7 timeouts);
fixing the runner is the next queue item.

lib/js/test262-slice/loops/do_while.expected

@@ -0,0 +1 @@
+3

lib/js/test262-slice/loops/do_while.js

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+let i = 0; do { i = i + 1; } while (i < 3); i

lib/js/test262-slice/loops/for_basic.expected

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+55

lib/js/test262-slice/loops/for_basic.js

@@ -0,0 +1 @@
+let s = 0; for (let i = 1; i <= 10; i = i + 1) s = s + i; s

lib/js/test262-slice/loops/for_break.expected

@@ -0,0 +1 @@
+6

lib/js/test262-slice/loops/for_break.js

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+let x = 0; for (let i = 0; i < 100; i = i + 1) { if (i === 7) break; x = i; } x

lib/js/test262-slice/loops/for_continue.expected

@@ -0,0 +1 @@
+25

lib/js/test262-slice/loops/for_continue.js

@@ -0,0 +1 @@
+let s = 0; for (let i = 0; i < 10; i = i + 1) { if (i % 2 === 0) continue; s = s + i; } s

lib/js/test262-slice/loops/nested_for.expected

@@ -0,0 +1 @@
+12

lib/js/test262-slice/loops/nested_for.js

@@ -0,0 +1 @@
+let n = 0; for (let i = 0; i < 3; i = i + 1) for (let j = 0; j < 4; j = j + 1) n = n + 1; n

lib/js/test262-slice/loops/while_basic.expected

@@ -0,0 +1 @@
+5

lib/js/test262-slice/loops/while_basic.js

@@ -0,0 +1 @@
+let x = 0; while (x < 5) { x = x + 1; } x

lib/js/test262-slice/loops/while_break_infinite.expected

@@ -0,0 +1 @@
+5

lib/js/test262-slice/loops/while_break_infinite.js

@@ -0,0 +1 @@
+let i = 0; while (true) { i = i + 1; if (i >= 5) break; } i