guality: Workaround for guality/pr59776.c testcase

guality: Workaround for guality/pr59776.c testcase

The test has been added 3 years before noipa attribute has been introduced,
but already at that point I wanted to avoid IPA opts getting into way,
most of the foo function is optimized away and the debug info just points
to the caller\s var.  With the recent modref/aliasing changes the caller's
store to the variable whose address it is passing to the function is
optimized away too.

I think we should just use noipa to avoid this, though perhaps longer term
we should think about some debug info improvements how to deal with that.

The caller had before dse1:
  # DEBUG BEGIN_STMT
  x.f = 5.0e+0;
  x.g = 6.0e+0;
  # DEBUG BEGIN_STMT
  foo (&x);
  # DEBUG BEGIN_STMT
  x ={v} {CLOBBER};
and the x.f and x.g stores are optimized away.  If we had a way to pretend
the memory contains those values anyway...

Tested on x86_64-linux, fixes the guality regressions
+FAIL: gcc.dg/guality/pr59776.c   -O1  -DPREVENT_OPTIMIZATION  line pr59776.c:17 s1.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O1  -DPREVENT_OPTIMIZATION  line pr59776.c:17 s1.g == 6.0
+FAIL: gcc.dg/guality/pr59776.c   -O1  -DPREVENT_OPTIMIZATION  line pr59776.c:20 s1.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O1  -DPREVENT_OPTIMIZATION  line pr59776.c:20 s1.g == 6.0
+FAIL: gcc.dg/guality/pr59776.c   -O1  -DPREVENT_OPTIMIZATION  line pr59776.c:20 s2.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O2  -DPREVENT_OPTIMIZATION  line pr59776.c:17 s1.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O2  -DPREVENT_OPTIMIZATION  line pr59776.c:17 s1.g == 6.0
+FAIL: gcc.dg/guality/pr59776.c   -O2  -DPREVENT_OPTIMIZATION  line pr59776.c:20 s1.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O2  -DPREVENT_OPTIMIZATION  line pr59776.c:20 s1.g == 6.0
+FAIL: gcc.dg/guality/pr59776.c   -O2  -DPREVENT_OPTIMIZATION  line pr59776.c:20 s2.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none  -DPREVENT_OPTIMIZATION line pr59776.c:17 s1.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none  -DPREVENT_OPTIMIZATION line pr59776.c:17 s1.g == 6.0
+FAIL: gcc.dg/guality/pr59776.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none  -DPREVENT_OPTIMIZATION line pr59776.c:20 s1.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none  -DPREVENT_OPTIMIZATION line pr59776.c:20 s1.g == 6.0
+FAIL: gcc.dg/guality/pr59776.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none  -DPREVENT_OPTIMIZATION line pr59776.c:20 s2.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  -DPREVENT_OPTIMIZATION line pr59776.c:17 s1.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  -DPREVENT_OPTIMIZATION line pr59776.c:17 s1.g == 6.0
+FAIL: gcc.dg/guality/pr59776.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  -DPREVENT_OPTIMIZATION line pr59776.c:20 s1.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  -DPREVENT_OPTIMIZATION line pr59776.c:20 s1.g == 6.0
+FAIL: gcc.dg/guality/pr59776.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  -DPREVENT_OPTIMIZATION line pr59776.c:20 s2.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O3 -g  -DPREVENT_OPTIMIZATION  line pr59776.c:17 s1.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O3 -g  -DPREVENT_OPTIMIZATION  line pr59776.c:17 s1.g == 6.0
+FAIL: gcc.dg/guality/pr59776.c   -O3 -g  -DPREVENT_OPTIMIZATION  line pr59776.c:20 s1.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -O3 -g  -DPREVENT_OPTIMIZATION  line pr59776.c:20 s1.g == 6.0
+FAIL: gcc.dg/guality/pr59776.c   -O3 -g  -DPREVENT_OPTIMIZATION  line pr59776.c:20 s2.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -Os  -DPREVENT_OPTIMIZATION  line pr59776.c:17 s1.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -Os  -DPREVENT_OPTIMIZATION  line pr59776.c:17 s1.g == 6.0
+FAIL: gcc.dg/guality/pr59776.c   -Os  -DPREVENT_OPTIMIZATION  line pr59776.c:20 s1.f == 5.0
+FAIL: gcc.dg/guality/pr59776.c   -Os  -DPREVENT_OPTIMIZATION  line pr59776.c:20 s1.g == 6.0
+FAIL: gcc.dg/guality/pr59776.c   -Os  -DPREVENT_OPTIMIZATION  line pr59776.c:20 s2.f == 5.0
introduced in the last 2 days.

2020-11-17  Jakub Jelinek  <jakub@redhat.com>

	* gcc.dg/guality/pr59776.c (foo): Use noipa attribute instead of
	noinline, noclone.