Don't do the check for clang/clang++.

Adding -Qunused-arguments to CXXFLAGS causes the checks for -f and -m
flags not to fail with clang++, causing the configure script to warn
about -f flags supported by clang but not clang++ indicating that the
compilers are a mismatched pair.

The checks we do for flags should eliminate "unused" -f/-m flags,
suppressing the warnings that way.

Change-Id: I749d6f499a3d34300518cc0ba539f355377359af
Reviewed-on: https://code.wireshark.org/review/2362
Reviewed-by: Guy Harris <guy@alum.mit.edu>

acinclude.m4

@@ -2137,45 +2137,3 @@ AC_DEFUN([AC_WIRESHARK_QT_CHECK],
 	fi
 
 ])
-
-#
-# AC_WIRESHARK_CLANG_CHECK
-#
-# Check if either our C or C++ compiler is Clang
-#
-AC_DEFUN([AC_WIRESHARK_CLANG_CHECK], [
-
-  AC_MSG_CHECKING(if $CC is Clang)
-  AC_COMPILE_IFELSE([
-    AC_LANG_SOURCE([[
-#ifndef __clang__
-CC is not __clang__
-#endif
-    ]])],
-    [
-      CC_IS_CLANG='yes'
-      CFLAGS="$CFLAGS"
-    ],
-    CC_IS_CLANG='no'
-    )
-  AC_MSG_RESULT($CC_IS_CLANG)
-
-  AC_MSG_CHECKING(if $CXX is Clang)
-  AC_LANG_PUSH([C++])
-  AC_COMPILE_IFELSE([
-    AC_LANG_SOURCE([[
-#ifndef __clang__
-CXX is not __clang__
-#endif
-    ]])],
-    [
-      CXX_IS_CLANG='yes'
-      CXXFLAGS="$CXXFLAGS -Qunused-arguments"
-    ],
-    CXX_IS_CLANG='no'
-    )
-  AC_LANG_POP([C++])
-  AC_MSG_RESULT($CXX_IS_CLANG)
-
-])
-

configure.ac

@@ -58,7 +58,6 @@ AM_PROG_CC_C_O
 AC_PROG_CXX
 AC_PROG_CPP
 AC_PROG_MKDIR_P
-AC_WIRESHARK_CLANG_CHECK
 
 dnl Work around libtool bug (fixed in the version 1.5a?)
 AC_DEFUN([AC_PROVIDE_AC_LIBTOOL_DLOPEN], )