patch 7.4.750
Problem: Cannot build with clang 3.5 on Cygwin with perl enabled.
Solution: Strip "-fdebug-prefix-map" in configure. (Ken Takata)
diff --git a/src/configure.in b/src/configure.in
index be3c658..80d70b0 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -942,8 +942,10 @@
done
AC_SUBST(vi_cv_perl_xsubpp)
dnl Remove "-fno-something", it breaks using cproto.
+ dnl Remove "-fdebug-prefix-map", it isn't supported by clang.
perlcppflags=`$vi_cv_path_perl -Mlib=$srcdir -MExtUtils::Embed \
- -e 'ccflags;perl_inc;print"\n"' | sed -e 's/-fno[[^ ]]*//'`
+ -e 'ccflags;perl_inc;print"\n"' | sed -e 's/-fno[[^ ]]*//' \
+ -e 's/-fdebug-prefix-map[[^ ]]*//g'`
dnl Remove "-lc", it breaks on FreeBSD when using "-pthread".
perllibs=`cd $srcdir; $vi_cv_path_perl -MExtUtils::Embed -e 'ldopts' | \
sed -e '/Warning/d' -e '/Note (probably harmless)/d' \