analyzer: fix uses of alloca in testsuite

analyzer: fix uses of alloca in testsuite

gcc/testsuite/ChangeLog:
	* gcc.dg/analyzer/call-summaries-2.c: Add
	dg-require-effective-target alloca.
	* gcc.dg/analyzer/imprecise-floating-point-1.c: Likewise.
	* gcc.dg/analyzer/infinite-recursion-alloca.c: Likewise.
	* gcc.dg/analyzer/malloc-callbacks.c: Likewise.
	* gcc.dg/analyzer/out-of-bounds-5.c: Likewise.  Remove includes
	of <stdio.h> and <alloca.h>.  Use "__builtin_free" rather than
	"free", to match uses of "__builtin_malloc".
	* gcc.dg/analyzer/putenv-1.c: Add dg-require-effective-target
	alloca.
	* gcc.dg/analyzer/write-to-string-literal-5.c: Likewise.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>