t-coffee #79

          when I use the same way to complie(```emscripten/emsdk:2.0.34```) software ```t_coffee``` (http://tcoffee-packages.s3-website.eu-central-1.amazonaws.com/#Stable/Latest/) to wasm and got ```t_coffee.wasm``` without error, but when run in Chrome get error:

[WebWorker] Executing t_coffee -seq=input.fa -reg    args=null
20b6be06-daba-47f1-bec0-8e1412abe74c:1 RuntimeError: unreachable
    at set_nproc(int) (t_coffee.wasm:0x1689fa)
    at t_coffee_dpa(int, char**) (t_coffee.wasm:0x4735be)
    at batch_main(int, char**) (t_coffee.wasm:0x4538ab)
    at main (t_coffee.wasm:0x44d553)
    at VM13 t_coffee.js:1581:22
    at Object.callMain (VM13 t_coffee.js:5618:15)
    at Object.exec (20b6be06-daba-47f1-bec0-8e1412abe74c:1:5793)
    at i (20b6be06-daba-47f1-bec0-8e1412abe74c:1:1015)

  (func $set_nproc(int) (;882;) (param $var0 i32) (result i32)
    (local $var1 i32)
    (local $var2 i32)
    (local $var3 i32)
    (local $var4 i32)
    (local $var5 i32)
    global.get $__stack_pointer
    local.set $var1
    i32.const 16
    local.set $var2
    local.get $var1
    local.get $var2
    i32.sub
    local.set $var3
    local.get $var3
    local.get $var0
    i32.store offset=12
    local.get $var3
    i32.load offset=12
    local.set $var4
    i32.const 0
    local.set $var5
    local.get $var5
    local.get $var4
    i32.store offset=696988
    unreachable
  )