build: assume sys/socket.h, sys/time.h on non-Windows (as in curl/curl.h)

Public `curl/curl.h` includes these headers for non-Windows platforms
without further conditions. This makes it safe to assume these headers
do exist, allowing to save two feature checks for non-Windows targets.

`sys/time.h` is also assumed on Windows with mingw-w64, for declaring
`gettimeofday()`.

Closes #17522

CMake/unix-cache.cmake

@@ -280,7 +280,6 @@ set(HAVE_SYS_PARAM_H 1)
 set(HAVE_SYS_POLL_H 1)
 set(HAVE_SYS_RESOURCE_H 1)
 set(HAVE_SYS_SELECT_H 1)
-set(HAVE_SYS_SOCKET_H 1)
 if(CYGWIN OR
    CMAKE_SYSTEM_NAME STREQUAL "Linux")
   set(HAVE_SYS_SOCKIO_H 0)

CMake/win32-cache.cmake

@@ -39,7 +39,6 @@ if(MINGW)
   set(HAVE_STDINT_H 1)  # detected by CMake internally in check_type_size()
   set(HAVE_STRINGS_H 1)  # wrapper to string.h
   set(HAVE_SYS_PARAM_H 1)
-  set(HAVE_SYS_TIME_H 1)
   set(HAVE_UNISTD_H 1)
   set(HAVE_UTIME_H 1)  # wrapper to sys/utime.h
 else()
@@ -50,7 +49,6 @@ else()
   set(HAVE_OPENDIR 0)
   set(HAVE_STRINGS_H 0)
   set(HAVE_SYS_PARAM_H 0)
-  set(HAVE_SYS_TIME_H 0)
   set(HAVE_UTIME_H 0)
   if(MSVC)
     set(HAVE_UNISTD_H 0)
@@ -170,7 +168,6 @@ set(HAVE_SYS_IOCTL_H 0)
 set(HAVE_SYS_POLL_H 0)
 set(HAVE_SYS_RESOURCE_H 0)
 set(HAVE_SYS_SELECT_H 0)
-set(HAVE_SYS_SOCKET_H 0)
 set(HAVE_SYS_SOCKIO_H 0)
 set(HAVE_SYS_STAT_H 1)
 set(HAVE_SYS_TYPES_H 1)

CMakeLists.txt

@@ -1663,6 +1663,18 @@ if(WIN32)
     set(HAVE_IF_NAMETOINDEX 0)
   endif()
   unset(HAVE_IF_NAMETOINDEX CACHE)
+
+  set(HAVE_SYS_TIME_H ${MINGW})
+else()
+  set(HAVE_SYS_SOCKET_H 1)
+  set(HAVE_SYS_TIME_H 1)
+endif()
+
+if(HAVE_SYS_SOCKET_H)
+  list(APPEND CURL_INCLUDES "sys/socket.h")
+endif()
+if(HAVE_SYS_TIME_H)
+  list(APPEND CURL_INCLUDES "sys/time.h")
 endif()
 
 # Detect headers
@@ -1677,10 +1689,8 @@ check_include_file("sys/param.h"      HAVE_SYS_PARAM_H)
 check_include_file("sys/poll.h"       HAVE_SYS_POLL_H)
 check_include_file("sys/resource.h"   HAVE_SYS_RESOURCE_H)
 check_include_file_concat_curl("sys/select.h"     HAVE_SYS_SELECT_H)
-check_include_file_concat_curl("sys/socket.h"     HAVE_SYS_SOCKET_H)
 check_include_file("sys/sockio.h"     HAVE_SYS_SOCKIO_H)
 check_include_file("sys/stat.h"       HAVE_SYS_STAT_H)
-check_include_file_concat_curl("sys/time.h"       HAVE_SYS_TIME_H)
 check_include_file_concat_curl("sys/types.h"      HAVE_SYS_TYPES_H)
 check_include_file("sys/un.h"         HAVE_SYS_UN_H)
 check_include_file_concat_curl("sys/utime.h"      HAVE_SYS_UTIME_H)  # sys/types.h (AmigaOS)

configure.ac

@@ -3959,13 +3959,18 @@ case "$OPT_FISH_FPATH" in
 esac
 AM_CONDITIONAL(USE_FISH_COMPLETION, test x"$FISH_FUNCTIONS_DIR" != x)
 
+if test "$curl_cv_native_windows" != 'yes'; then
+  AC_DEFINE(HAVE_SYS_SOCKET_H, 1, [if you have <sys/socket.h>])
+  AC_DEFINE(HAVE_SYS_TIME_H, 1, [if you have <sys/time.h>])
+  HAVE_SYS_SOCKET_H=1
+  HAVE_SYS_TIME_H=1
+fi
+
 dnl Now check for the very most basic headers. Then we can use these
 dnl ones as default-headers when checking for the rest!
 AC_CHECK_HEADERS(
   sys/types.h \
-  sys/time.h \
   sys/select.h \
-  sys/socket.h \
   sys/ioctl.h \
   unistd.h \
   arpa/inet.h \