Fix #1924: Emit SPV_EXT_physical_storage_buffer, not the KHR form.
The KHR form comes along as part of 1.5, and otherwise should require
another form of request to emit it.
diff --git a/Test/baseResults/spv.bufferhandle3.frag.out b/Test/baseResults/spv.bufferhandle3.frag.out
index b888fe4..c02c34c 100644
--- a/Test/baseResults/spv.bufferhandle3.frag.out
+++ b/Test/baseResults/spv.bufferhandle3.frag.out
@@ -5,7 +5,7 @@
Capability Shader
Capability PhysicalStorageBufferAddressesEXT
- Extension "SPV_KHR_physical_storage_buffer"
+ Extension "SPV_EXT_physical_storage_buffer"
Extension "SPV_KHR_storage_buffer_storage_class"
1: ExtInstImport "GLSL.std.450"
MemoryModel PhysicalStorageBuffer64EXT GLSL450