Add perf test for Proxy get
Add perf test for Proxy get

Missing from a previous pull.

svaarala/duktape,markand/duktape,svaarala/duktape,markand/duktape,markand/duktape,svaarala/duktape,markand/duktape,svaarala/duktape,svaarala/duktape,svaarala/duktape,svaarala/duktape,markand/duktape,svaarala/duktape,markand/duktape,markand/duktape,markand/duktape,markand/duktape,svaarala/duktape,markand/duktape