libuv: Remove unused compatibility code for CMake < 3.9

We now require CMake 3.13 or higher anyway.

Utilities/cmlibuv/CMakeLists.txt

@@ -297,10 +297,6 @@ if(CMAKE_SYSTEM_NAME STREQUAL "SunOS")
     )
   if(CMAKE_SYSTEM_VERSION STREQUAL "5.10")
     set(CMAKE_C_STANDARD 90)
-    if(CMAKE_VERSION VERSION_LESS 3.8.20170504 AND CMAKE_C_COMPILER_ID STREQUAL "SunPro" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.14)
-      # The running version of CMake does not know how to add this flag.
-      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c90")
-    endif()
     list(APPEND uv_defines
       _XOPEN_SOURCE=500
       )
@@ -308,10 +304,6 @@ if(CMAKE_SYSTEM_NAME STREQUAL "SunOS")
     if(NOT CMAKE_C_STANDARD OR CMAKE_C_STANDARD EQUAL 90)
       set(CMAKE_C_STANDARD 11)
     endif()
-    if(CMAKE_VERSION VERSION_LESS 3.8.20170505 AND CMAKE_C_COMPILER_ID STREQUAL "SunPro" AND CMAKE_C_COMPILER_VERSION VERSION_LESS 5.14)
-      # The running version of CMake does not know how to add this flag.
-      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -xc99")
-    endif()
     list(APPEND uv_defines
       _XOPEN_SOURCE=600
       )