[autoconf] Fix 80+ and quoting.

Additional quoting for safety and satisfying newer autotools.  Fix a couple of 80 column violations.

http://llvm-reviews.chandlerc.com/D333

Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173877 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/configure b/configure
index d468759..1ad1dac 100755
--- a/configure
+++ b/configure
@@ -19897,6 +19897,7 @@
 fi
 
 
+
 { echo "$as_me:$LINENO: checking for isinf in <math.h>" >&5
 echo $ECHO_N "checking for isinf in <math.h>... $ECHO_C" >&6; }
 if test "${ac_cv_func_isinf_in_math_h+set}" = set; then