Report heap overflow in the same way as stack overflow

Now that we throw an exception for heap overflow, we should only print
the heap overflow message in the main thread when the HeapOverflow
exception is caught, rather than as a side effect in the GC.

Stack overflows were already done this way, I just made heap overflow
consistent with stack overflow, and did some related cleanup.

Fixes broken T2592(profasm) which was reporting the heap overflow
message twice (you would only notice when building with profiling
libs enabled).

Test Plan: validate

Reviewers: bgamari, niteria, austin, DemiMarie, hvr, erikd

Reviewed By: bgamari

Subscribers: rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3394

1 files changed, 0 insertions, 2 deletions

diff --git a/rts/RtsUtils.h b/rts/RtsUtils.h
index 8f4e8066f2..6514e351d1 100644
--- a/rts/RtsUtils.h
+++ b/rts/RtsUtils.h
@@ -34,8 +34,6 @@ void stgFree(void* p);
  * Misc other utilities
  * -------------------------------------------------------------------------- */
 
-void heapOverflow(void);
-
 char *time_str(void);
 char *showStgWord64(StgWord64, char *, bool);