Ensure that :checkhealth is happy with the Gentoo build type.
https://bugs.gentoo.org/757744
--- a/runtime/autoload/health/nvim.vim
+++ b/runtime/autoload/health/nvim.vim
@@ -135,7 +135,7 @@ function! s:check_performance() abort
   let buildtype = matchstr(execute('version'), '\v\cbuild type:?\s*[^\n\r\t ]+')
   if empty(buildtype)
     call health#report_error('failed to get build type from :version')
-  elseif buildtype =~# '\v(MinSizeRel|Release|RelWithDebInfo)'
+  elseif buildtype =~# '\v(MinSizeRel|Release|RelWithDebInfo|Gentoo)'
     call health#report_ok(buildtype)
   else
     call health#report_info(buildtype)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -137,12 +137,6 @@ else()
   message(STATUS "MIN_LOG_LEVEL=${MIN_LOG_LEVEL}")
 endif()
 
-# Default to -O2 on release builds.
-if(CMAKE_C_FLAGS_RELEASE MATCHES "-O3")
-  message(STATUS "Replacing -O3 in CMAKE_C_FLAGS_RELEASE with -O2")
-  string(REPLACE "-O3" "-O2" CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE}")
-endif()
-
 if(CMAKE_C_COMPILER_ID MATCHES "GNU")
   check_c_compiler_flag(-Og HAS_OG_FLAG)
 else()