[Patch] Fix compilation time explosion in contains_label_p

[Eric Botcazou]

Hi,

the attached testcase (with -gnato) triggers a compilation time explosion in 
contains_label_p because the tree passed to it contains many shared nodes, 
which are then walked multiple time.

Tested on i586-suse-linux, OK for mainline?


2009-06-28  Eric Botcazou  <ebotcazou@adacore.com>

	* fold-const.c: Include pointer-set.h.
	(contains_label_p): Do not walk trees multiple time.
	* Makefile.in (fold-const.o): Add dependency on pointer-set.h.


2009-06-28  Eric Botcazou  <ebotcazou@adacore.com>

	* gnat.dg/overflow_sum2.adb: New test
	* gnat.dg/namet.ads: New helper.


-- 
Eric Botcazou
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