Configure: fixed detection of newer Apple clang compilers.

auto/cc/clang

diff --git a/auto/cc/clang b/auto/cc/clang
index 9f60d7b..2611caa 100644
--- a/auto/cc/clang
+++ b/auto/cc/clang
@@ -5,8 +5,8 @@
 # clang
 
 
-NGX_CLANG_VER=`$CC -v 2>&1 | grep 'clang version' 2>&1 \
-                           | sed -e 's/^.*clang version \(.*\)/\1/'`
+NGX_CLANG_VER=`$CC -v 2>&1 | grep '\(clang\|LLVM\) version' 2>&1 \
+                           | sed -e 's/^.* version \(.*\)/\1/'`
 
 echo " + clang version: $NGX_CLANG_VER"
 

auto/cc/name

diff --git a/auto/cc/name b/auto/cc/name
index 7a5656c..51a7ed9 100644
--- a/auto/cc/name
+++ b/auto/cc/name
@@ -67,7 +67,7 @@
     NGX_CC_NAME=gcc
     echo " + using GNU C compiler"
 
-elif `$CC -v 2>&1 | grep 'clang version' >/dev/null 2>&1`; then
+elif `$CC -v 2>&1 | grep '\(clang\|LLVM\) version' >/dev/null 2>&1`; then
     NGX_CC_NAME=clang
     echo " + using Clang C compiler"