Only use PGO data on recent enough clang

Contributes to #34649 and fixes the Codespaces prebuild.

Author: akoeplinger

src/coreclr/pgosupport.cmake

@@ -52,17 +52,17 @@ function(add_pgo TargetName)
                 add_compile_definitions(WITH_NATIVE_PGO)
             else(CLR_CMAKE_HOST_WIN32)
                 if(UPPERCASE_CMAKE_BUILD_TYPE STREQUAL RELEASE OR UPPERCASE_CMAKE_BUILD_TYPE STREQUAL RELWITHDEBINFO)
-                    if((CMAKE_CXX_COMPILER_ID MATCHES "Clang") AND (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 16))
+                    if((CMAKE_CXX_COMPILER_ID MATCHES "Clang") AND (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 20))
                         if(HAVE_LTO)
                             target_compile_options(${TargetName} PRIVATE -flto -fprofile-instr-use=${ProfilePath} -Wno-profile-instr-out-of-date -Wno-profile-instr-unprofiled)
                             set_property(TARGET ${TargetName} APPEND_STRING PROPERTY LINK_FLAGS " -flto -fprofile-instr-use=${ProfilePath}")
                             add_compile_definitions(WITH_NATIVE_PGO)
                         else(HAVE_LTO)
                             message(WARNING "LTO is not supported, skipping profile guided optimizations")
                         endif(HAVE_LTO)
-                    else((CMAKE_CXX_COMPILER_ID MATCHES "Clang") AND (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 16))
-                        message(WARNING "PGO is not supported; Clang 16 or later is required for profile guided optimizations")
-                    endif((CMAKE_CXX_COMPILER_ID MATCHES "Clang") AND (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 16))
+                    else((CMAKE_CXX_COMPILER_ID MATCHES "Clang") AND (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 20))
+                        message(WARNING "PGO is not supported; Clang 20 or later is required for profile guided optimizations")
+                    endif((CMAKE_CXX_COMPILER_ID MATCHES "Clang") AND (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 20))
                 endif(UPPERCASE_CMAKE_BUILD_TYPE STREQUAL RELEASE OR UPPERCASE_CMAKE_BUILD_TYPE STREQUAL RELWITHDEBINFO)
             endif(CLR_CMAKE_HOST_WIN32)
         endif(NOT EXISTS ${ProfilePath})