Roll external/spirv-headers/ 4bd8fc0c8..85a1ed200 (4 commits)

https://github.com/KhronosGroup/SPIRV-Headers/compare/4bd8fc0c8c26...85a1ed200d50

$ git log 4bd8fc0c8..85a1ed200 --date=short --no-merges --format='%ad %ae %s'
2022-10-05 dkoch Fix extension for RayTracingOpacityMicromapEXT
2022-10-04 kpet Add support for texel buffers to clspv non-semantic instruction set
2022-10-04 hugo registered ID for Shady
2022-08-23 ewerness VK_EXT_opacity_micromap

Created with:
  roll-dep external/spirv-headers
diff --git a/DEPS b/DEPS
index e054df4..3a5f614 100644
--- a/DEPS
+++ b/DEPS
@@ -6,7 +6,7 @@
   'effcee_revision': '35912e1b7778ec2ddcff7e7188177761539e59e0',
   'googletest_revision': 'd9bb8412d60b993365abb53f00b6dad9b2c01b62',
   're2_revision': 'd2836d1b1c34c4e330a85a1006201db474bf2c8a',
-  'spirv_headers_revision': '4bd8fc0c8c266ecc6fc50193e65fe6a2fff8e4bc',
+  'spirv_headers_revision': '85a1ed200d50660786c1a88d9166e871123cce39',
 }
 
 deps = {