ICE on misuse of Float::powf(), Float::exp(), Float::exp2(), Float::ln(), etc.

[porglezomp]

The following code ICEs

fn main() {
    Float::exp2(2.0f32); // Misuse produces ICE
}

Using the function correctly works, but I misread docs, it goes against C style and I'm not used to it, etc. etc.
It produces the following error:

error: internal compiler error: unexpected failure
note: the compiler hit an unexpected failure path. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace

task 'rustc' failed at 'assertion failed: `(left == right) && (right == left)` (left: `3`, right: `0`)', /Users/rustbuild/src/rust-buildbot/slave/nightly-mac/build/src/librustc/middle/trans/callee.rs:528

stack backtrace:
   1:        0x11122eba9 - rt::backtrace::imp::write::h37f6a875ac6b1faadTq
   2:        0x111231e77 - failure::on_fail::ha0d7c2b5d797210dM9q
   3:        0x1114a72d5 - unwind::begin_unwind_inner::h8592212a9677a640bwd
   4:        0x1114a6f9c - unwind::begin_unwind_fmt::h6219a3bbf23fbac6Dtd
   5:        0x10e217aa5 - middle::trans::callee::trans_fn_ref_with_substs::h6f096e8e3f688f10tp3
   6:        0x10e214e51 - middle::trans::callee::trans_fn_ref::h7bbccdac16804408gd3
   7:        0x10e21dddb - middle::trans::callee::trans_call::closure.123295
   8:        0x10e1f6b14 - middle::trans::callee::trans_call_inner::h55aaa0a7bde8582abL3
   9:        0x10e21d4c7 - middle::trans::callee::trans_call::h7b4e2c8e6df15e7cwF3
  10:        0x10e22cf91 - middle::trans::expr::trans_rvalue_dps_unadjusted::h39b1e2c3f738ff77VT5
  11:        0x10e1eefd9 - middle::trans::expr::trans_into::hf8cf7932e7f2154etv4
  12:        0x10e1ee32c - middle::trans::controlflow::trans_stmt_semi::he272bee55161ef1fHK0
  13:        0x10e1ed9a0 - middle::trans::controlflow::trans_stmt::h0390fed190759d5fuG0
  14:        0x10e1ef228 - middle::trans::controlflow::trans_block::h7c868ed020abce21AL0
  15:        0x10e297ec2 - middle::trans::base::trans_closure::h25d2de8e59a72d7aDRg
  16:        0x10e1e200a - middle::trans::base::trans_fn::h10877aed033d0a4512g
  17:        0x10e1df745 - middle::trans::base::trans_item::h97c8a79a0f0fc5f8kmh
  18:        0x10e2a1308 - middle::trans::base::trans_crate::hccecf7aaa4e46ab47ji
  19:        0x10e6e5825 - driver::driver::phase_4_translate_to_llvm::h84739236ba6c4727RkA
  20:        0x10e6de1c6 - driver::driver::compile_input::h00dbfd22819e945aMRz
  21:        0x10e764a4f - driver::run_compiler::h328a12ddeecb656e6ED
  22:        0x10e762c26 - driver::run::closure.145941
  23:        0x10de75ffb - task::TaskBuilder<S>::try_future::closure.103316
  24:        0x10de75ee3 - task::TaskBuilder<S>::spawn_internal::closure.103287
  25:        0x10f07179d - task::spawn_opts::closure.8545
  26:        0x11150e89c - rust_try_inner
  27:        0x11150e886 - rust_try
  28:        0x1114a4947 - unwind::try::h830831e09adce3e0Tkd
  29:        0x1114a47cc - task::Task::run::h2ebb757597a20ac34Ac
  30:        0x10f0715c2 - task::spawn_opts::closure.8484
  31:        0x1114a618a - thread::thread_start::h2b706d41aa520cb4fVc
  32:     0x7fff87d6b772 - _pthread_start

[alexcrichton]

cc @nick29581, looks UFCS-related

[nrc]

dup of #18061, should be fixed by #18177

[nrc]

Please re-open if this doesn't get fixed