Revert "Float only writeColor"

This reverts commit 978e2469e6b98de6784c27cbba69121e054f4351.

Reason for revert: Potentially causing some failures in https://angle-gold.skia.org/diff?grouping=name%3Dhearthstone%26source_type%3Dangle&left=f9178a683907f1c8d806c0970e2468c2&right=af6167f064bfd553d11eaed8d1abb29f&changelist_id=4098332&crs=gerrit

Change-Id: Ie7363edbf4e32a886d0732269c5584248f6a508b
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/70329
Reviewed-by: Alexis Hétu <sugoi@google.com>
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@google.com>
diff --git a/src/Vulkan/BUILD.gn b/src/Vulkan/BUILD.gn
index a7703f0..5556abd 100644
--- a/src/Vulkan/BUILD.gn
+++ b/src/Vulkan/BUILD.gn
@@ -63,6 +63,7 @@
 
   defines += [
      "SWIFTSHADER_ENABLE_ASTC",  # TODO(b/150130101)
+     "SWIFTSHADER_LEGACY_PRECISION=true",  # TODO(chromium:1299047)
      "SWIFTSHADER_ZERO_INITIALIZE_DEVICE_MEMORY",
   ]
 }