bug#17136: [PATCH] dfa: speed up memory allocation, port to IRIX

[Paul Eggert]

I merged that patch into the grep trunk and am closing this bug report. 
 While merging, I removed one part of the patch that had a small but 
measurable performance degradation, namely, the introduction of struct 
dfatab.  I found some other minor simplifications and threw them in. 
There seems to be no significant change in CPU performance.  The patch's 
causes the dfa module's text size to shrink by 8% on my platform (x86-64 
Fedora 20), which I suppose is a small win, but the main point of the 
patch is simplifying the source.  I'm attaching what I installed, broken 
into 12 little patches to ease review.

0001-dfa-clarify-memory-allocation-and-port-to-IRIX.patch
Description: Text document

0002-dfa-avoid-unnecessary-work-and-other-initialization.patch
Description: Text document

0003-dfa-better-size-overflow-check.patch
Description: Text document

0004-dfa-simplify-transition-table-allocation.patch
Description: Text document

0005-dfa-simplify-range-char-allocation.patch
Description: Text document

0006-dfa-simplify-multibyte_prop-allocation.patch
Description: Text document

0007-dfa-simplify-position-set-and-element-count-allocati.patch
Description: Text document

0008-dfa-simplify-memory-allocation.patch
Description: Text document

0009-dfa-avoid-duplicate-strlen-when-allocating-memory.patch
Description: Text document

0010-dfa-simplify-freelist.patch
Description: Text document

0011-dfa-simplify-dfmust-initialization.patch
Description: Text document

0012-dfa-trans-reallocation-microoptimization.patch
Description: Text document