Merge branch 'master' into harmony-v2.8.6

README.md

@@ -75,8 +75,6 @@ The available options are:
   --support-ie8                 Use this flag to support Internet Explorer 6/7/8.
                                 Equivalent to setting `screw_ie8: false` in `minify()`
                                 for `compress`, `mangle` and `output` options.
-                                Note: `--support-ie8` may generate incorrect code
-                                for `try`/`catch` in ES5 compliant browsers.
   --expr                        Parse a single expression, rather than a
                                 program (for parsing JSON)
   -p, --prefix                  Skip prefix for original filenames that appear
@@ -350,6 +348,9 @@ to set `true`; it's effectively a shortcut for `foo=true`).
   comparison are switching. Compression only works if both `comparisons` and
   `unsafe_comps` are both set to true.
 
+- `unsafe_math` (default: false) -- optimize numerical expressions like
+  `2 * x * 3` into `6 * x`, which may give imprecise floating point results.
+
 - `unsafe_proto` (default: false) -- optimize expressions like
   `Array.prototype.slice.call(a)` into `[].slice.call(a)`
 
@@ -423,6 +424,9 @@ to set `true`; it's effectively a shortcut for `foo=true`).
   such as `console.info` and/or retain side effects from function arguments
   after dropping the function call then use `pure_funcs` instead.
 
+- `expression` -- default `false`.  Pass `true` to preserve completion values
+  from terminal statements without `return`, e.g. in bookmarklets.
+
 - `keep_fargs` -- default `true`.  Prevents the
   compressor from discarding unused function arguments.  You need this
   for code which relies on `Function.length`.