rts: Fix potential memory leak in ProfHeap.c

Discovered by Coverity. CID 43166.

Signed-off-by: Austin Seipp <austin@well-typed.com>
(cherry picked from commit 95da409719bab6f92229dc1a632c471e248d2fdd)
rts: Fix possible int overflow in resize_nursery

n_capabilities is declared as unsigned int (32bit), and so multiplication
is 32-bit before being stored in a 64bit integer (StgWord).

Instead, cast n_capabilities to StgWord before multiplying.

Discovered by Coverity. CID 43164.

Signed-off-by: Austin Seipp <austin@well-typed.com>
(cherry picked from commit 111b8454cc1b64da5b9816b89d79f44a8ae24355)
Check return value of sigaction

Issue discovered by Coverity scan, CID 43142.

Signed-off-by: Austin Seipp <austin@well-typed.com>
(cherry picked from commit f2595fd9d03803874df792072292d792a2c03bce)
Fix potential out-of-bound memory access

Issue discovered by Coverity scan, CID 43165.

Signed-off-by: Austin Seipp <austin@well-typed.com>
(cherry picked from commit fa0cbd297ba12e02273efcaa5f52fe76e10b7126)
Check correct variable for NULL

Issue discovered by Coverity scan, CID 43163. This should fix CID 43172 as a
side-effect as well.

Signed-off-by: Austin Seipp <austin@well-typed.com>
(cherry picked from commit 6ed7123dcc24c343a1ece85c7aa72ac1c34e6aff)
Fix memleak in hp2ps

Issue discovered by Coverity scan, CID 43167.

Signed-off-by: Austin Seipp <austin@well-typed.com>
(cherry picked from commit f17dcf09a5797bbefe22aef7d4c508d1672484df)