The main goal here is to reduce fragmentation, which turns out to be the case of #743. While I was here I found some opportunities to improve performance too. The code is rather more complex, but it also contains a long comment describing the strategy, so please take a look at that for the details.
People keep complaining, with some justification, that runST $ foo doesn't work. So I've finally caved in. The difficulty with the above is that we need to decide how to instantiate ($)'s type arguments based on the first argument (runST), and then use that info to check the second argumnent. There is a left-to-right flow of information. It's not hard to implement this, and it's clearly useful. The main change is in TcExpr.tcArgs, with some knock-on effects elsewhere. I was finally provoked into this by Trac #981, which turned out, after some head-scratching, to be another instance of the same problem. (There was some bug-fixing too; a type like ((?x::Int) => ...) is a polytype even though it has no leading for-alls, but the new TcUnify code was not treating it right.) Test for this is tc222
Work around the PowerPC architecture's +-32KB limitation for conditional branches by conditionally skipping an unconditional branch instead (unconditional branches have a +-32MB range). This requires an extra pass over the basic blocks for each CmmTop after block sequencing, to determine which branches are "far". Fixes ticket #709, "Fixup too large" error with -fasm on PowerPC
conc021 is an example of a program that broke. It doesn't handle them particularly well still, but it doesn't crash at least.
- Added HPCRIX support for passing tracer filename. - Added thread tracing support. - Cleaned up use of HsFFI.h
Also move closeMutex() etc. into freeTaskManager, this is a free-ish thing