[Flang][AMDGPU] Change default AMDHSA Code Object version to 5 (#87464)

This is a follow-up of PR:
#79038

Author: DominikAdamski

flang/include/flang/Frontend/CodeGenOptions.h

@@ -87,7 +87,7 @@ class CodeGenOptions : public CodeGenOptionsBase {
 
   /// \brief Code object version for AMDGPU.
   llvm::CodeObjectVersionKind CodeObjectVersion =
-      llvm::CodeObjectVersionKind::COV_4;
+      llvm::CodeObjectVersionKind::COV_5;
 
   /// Optimization remark with an optional regular expression pattern.
   struct OptRemark {

flang/test/Lower/AMD/code-object-version.f90

@@ -5,8 +5,8 @@
 !RUN: %flang_fc1 -emit-hlfir -triple amdgcn-amd-amdhsa -target-cpu gfx908 -mcode-object-version=5 %s -o - | FileCheck  --check-prefix=COV_5 %s
 !RUN: %flang_fc1 -emit-hlfir -triple amdgcn-amd-amdhsa -target-cpu gfx908 -mcode-object-version=6 %s -o - | FileCheck  --check-prefix=COV_6 %s
 
-!COV_DEFAULT: llvm.mlir.global weak_odr hidden local_unnamed_addr constant @__oclc_ABI_version(400 : i32) {addr_space = 4 : i32} : i32
-!COV_NONE-NOT: llvm.mlir.global weak_odr hidden local_unnamed_addr constant @__oclc_ABI_version(400 : i32) {addr_space = 4 : i32} : i32
+!COV_DEFAULT: llvm.mlir.global weak_odr hidden local_unnamed_addr constant @__oclc_ABI_version(500 : i32) {addr_space = 4 : i32} : i32
+!COV_NONE-NOT: llvm.mlir.global weak_odr hidden local_unnamed_addr constant @__oclc_ABI_version(500 : i32) {addr_space = 4 : i32} : i32
 !COV_4: llvm.mlir.global weak_odr hidden local_unnamed_addr constant @__oclc_ABI_version(400 : i32) {addr_space = 4 : i32} : i32
 !COV_5: llvm.mlir.global weak_odr hidden local_unnamed_addr constant @__oclc_ABI_version(500 : i32) {addr_space = 4 : i32} : i32
 !COV_6: llvm.mlir.global weak_odr hidden local_unnamed_addr constant @__oclc_ABI_version(600 : i32) {addr_space = 4 : i32} : i32