Panic (something to do with floatExpr?)

main = let (x :: String) = "hello" in putStrLn x

using a very simple driver for the GHC API (see T145.hs) causes a ghc panic:

[1 of 1] Compiling Main             ( T145-input.hs, interpreted )
T145: T145: panic! (the 'impossible' happened)
  (GHC version 7.10.0.20150128 for x86_64-apple-darwin):
	floatExpr tick
<<details unavailable>>

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

This panic is arising in our test case for #8333 (closed), so it may be related to that bug.

Trac metadata

Trac field	Value
Version	7.10.1-rc2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
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Blocking
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Operating system
Architecture

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