lib/os: Push simulation test down into intel_require_memory

This has the upside that we'll never forget to add it to thrashing
tests. But we'll also never miss to move it when adding basic
functionality tests to existing binaries. Chris already started this
refining work in e.g.

commit d77eda6614
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Fri Nov 14 07:45:40 2014 +0000

    igt/gem_linear_blits: Require that we do the full test

by moving igt_skip_on_simulation into subtests.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

tests/gem_evict_alignment.c

@@ -191,8 +191,6 @@ igt_main
 {
 	int size, count;
 
-	igt_skip_on_simulation();
-
 	igt_fixture {
 		fd = drm_open_any();
 	}

tests/gem_evict_everything.c

@@ -182,8 +182,6 @@ igt_main
 	size = count = 0;
 	fd = -1;
 
-	igt_skip_on_simulation();
-
 	igt_fixture {
 		fd = drm_open_any();
 

tests/gem_linear_blits.c

@@ -264,8 +264,6 @@ int main(int argc, char **argv)
 	igt_subtest("normal") {
 		int count;
 
-		igt_skip_on_simulation();
-
 		count = 3 * gem_aperture_size(fd) / (1024*1024) / 2;
 		igt_require(count > 1);
 		intel_require_memory(count, sizeof(linear), CHECK_RAM);
@@ -275,8 +273,6 @@ int main(int argc, char **argv)
 	igt_subtest("interruptible") {
 		int count;
 
-		igt_skip_on_simulation();
-
 		count = 3 * gem_aperture_size(fd) / (1024*1024) / 2;
 		igt_require(count > 1);
 		intel_require_memory(count, sizeof(linear), CHECK_RAM);

tests/gem_tiled_blits.c

@@ -214,8 +214,6 @@ int main(int argc, char **argv)
 	igt_subtest("normal") {
 		int count;
 
-		igt_skip_on_simulation();
-
 		count = 3 * gem_aperture_size(fd) / (1024*1024) / 2;
 		count += (count & 1) == 0;
 		intel_require_memory(count, 1024*1024, CHECK_RAM);
@@ -226,8 +224,6 @@ int main(int argc, char **argv)
 	igt_subtest("interruptible") {
 		int count;
 
-		igt_skip_on_simulation();
-
 		count = 3 * gem_aperture_size(fd) / (1024*1024) / 2;
 		count += (count & 1) == 0;
 		intel_require_memory(count, 1024*1024, CHECK_RAM);

tests/gem_tiled_swapping.c

@@ -150,7 +150,6 @@ igt_simple_main
 
 	current_tiling_mode = I915_TILING_X;
 
-	igt_skip_on_simulation();
 	intel_purge_vm_caches();
 
 	fd = drm_open_any();

tests/gem_userptr_blits.c

@@ -1240,8 +1240,6 @@ int main(int argc, char **argv)
 {
 	int size = sizeof(linear);
 
-	igt_skip_on_simulation();
-
 	igt_subtest_init(argc, argv);
 
 	igt_fixture {