ubsan: Ignore errors from SwiftShader

More errors exposed by the bots when trying to land this roll:
https://chromium-review.googlesource.com/c/angle/angle/+/4070947

Test: angle_deqp_gles31_tests --use-angle=swiftshader
Bug: angleproject:7852
Change-Id: I38e669817382ee17c403fbfd54ab2282a3f78cf0
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4072219
Reviewed-by: Amirali Abdolrashidi <abdolrashidi@google.com>
Commit-Queue: Cody Northrop <cnorthrop@google.com>
diff --git a/tools/ubsan/ignorelist.txt b/tools/ubsan/ignorelist.txt
index 019d9f0..bcd9697 100644
--- a/tools/ubsan/ignorelist.txt
+++ b/tools/ubsan/ignorelist.txt
@@ -8,4 +8,5 @@
 [alignment]
 src:*src/libANGLE/renderer/vulkan/SecondaryCommandBuffer*
 src:*third_party/zlib*
+src:*third_party/SwiftShader*