SpirvShader: Move extension list out of for loop.

Addresses the review comment:
https://swiftshader-review.googlesource.com/c/SwiftShader/+/39885/3/src/Pipeline/SpirvShader.cpp#422

Bug: b/145351270
Change-Id: I9a5ceefe048e63e0f52b7e9a15bd84f6bac16629
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/39955
Tested-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
diff --git a/src/Pipeline/SpirvShader.cpp b/src/Pipeline/SpirvShader.cpp
index 55ea1c3..be6125e 100644
--- a/src/Pipeline/SpirvShader.cpp
+++ b/src/Pipeline/SpirvShader.cpp
@@ -416,12 +416,13 @@
 
 			case spv::OpExtInstImport:
 			{
+				auto const extensionsByName = std::initializer_list<std::pair<const char *, Extension::Name>>{
+					{ "GLSL.std.450", Extension::GLSLstd450 },
+				};
 				auto id = Extension::ID(insn.word(1));
 				auto name = insn.string(2);
 				auto ext = Extension{ Extension::Unknown };
-				for(auto it : std::initializer_list<std::pair<const char *, Extension::Name>>{
-				        { "GLSL.std.450", Extension::GLSLstd450 },
-				    })
+				for(auto it : extensionsByName)
 				{
 					if(0 == strcmp(name, it.first))
 					{