Fix testOptLevel

Recreate LLPC context between iterations. The LLPC context is not
meant to be reused.

Related to #2434.
Fixes check-amdllpc-units on Windows.

llpc/unittests/context/testOptLevel.cpp

@@ -48,8 +48,6 @@ TEST(LlpcContextTests, MatchPipelineOptLevel) {
 
   LgcContext::initialize();
 
-  Context *context = new Context(GfxIp);
-
 #if LLVM_MAIN_REVISION && LLVM_MAIN_REVISION < 474768
   // Old version of the code
   for (auto optLevel : {Level::None, Level::Less, Level::Default, Level::Aggressive}) {
@@ -59,6 +57,9 @@ TEST(LlpcContextTests, MatchPipelineOptLevel) {
   for (auto optLevel :
        {CodeGenOptLevel::None, CodeGenOptLevel::Less, CodeGenOptLevel::Default, CodeGenOptLevel::Aggressive}) {
 #endif
+
+    Context *context = new Context(GfxIp);
+
     GraphicsPipelineBuildInfo pipelineInfo = {};
     pipelineInfo.options.optimizationLevel = static_cast<uint32_t>(optLevel);
 
@@ -90,6 +91,9 @@ TEST(LlpcContextTests, MatchPipelineOptLevel) {
   for (auto optLevel :
        {CodeGenOptLevel::None, CodeGenOptLevel::Less, CodeGenOptLevel::Default, CodeGenOptLevel::Aggressive}) {
 #endif
+
+    Context *context = new Context(GfxIp);
+
     ComputePipelineBuildInfo pipelineInfo = {};
     pipelineInfo.options.optimizationLevel = static_cast<uint32_t>(optLevel);