[spirv] allow debug info generation to use full optmization (#3201)

As SPIRV-Tools supports the debug info preservation for the full
optimization, we want to allow DXC users to use the full optimization
for the debug info generation.

This change updates SPIRV-Tools and SPIRV-Headers.

external/SPIRV-Headers

@@ -1 +1 @@
-Subproject commit 060627f0b0d2fa8581b5acb939f46e3b9e500593
+Subproject commit c43a43c7cc3af55910b9bec2a71e3e8a622443cf

external/SPIRV-Tools

@@ -1 +1 @@
-Subproject commit 9e17b9d07a2536dc0a717ba0ed7c419659400078
+Subproject commit 5c64374dd6cbfff1294ec78cdae1bc9de870a07d

tools/clang/lib/SPIRV/SpirvEmitter.cpp

@@ -587,8 +587,7 @@ void SpirvEmitter::HandleTranslationUnit(ASTContext &context) {
     needsLegalization = needsLegalization ||
                         declIdMapper.requiresLegalization() ||
                         spirvOptions.flattenResourceArrays ||
-                        declIdMapper.requiresFlatteningCompositeResources() ||
-                        spirvOptions.debugInfoRich;
+                        declIdMapper.requiresFlatteningCompositeResources();
 
     // Run legalization passes
     if (needsLegalization) {
@@ -606,8 +605,7 @@ void SpirvEmitter::HandleTranslationUnit(ASTContext &context) {
     }
 
     // Run optimization passes
-    if (!spirvOptions.debugInfoRich &&
-        theCompilerInstance.getCodeGenOpts().OptimizationLevel > 0) {
+    if (theCompilerInstance.getCodeGenOpts().OptimizationLevel > 0) {
       std::string messages;
       if (!spirvToolsOptimize(&m, &messages)) {
         emitFatalError("failed to optimize SPIR-V: %0", {}) << messages;