Adapt configure.ac check to new Clang -fno-sanitize-recover=... syntax

...in Clang trunk towards 3.7 (ugly to come up with a standards-conforming sed
BRE, though)

Change-Id: I82196433ad153ae29b92ab15e58d6806ec4ccf26

configure.ac

@@ -11203,7 +11203,8 @@ int main(int argc, char **argv) {
             #               ^~~~~~~~~~~~~~~~~~~~~~~
             #               vptr for 'QObjectPrivate'
             save_CXX=$CXX
-            CXX=$(printf %s "$CXX" | sed -e s/-fno-sanitize-recover//)
+            CXX=$(printf %s "$CXX"
+                | sed -e s/-fno-sanitize-recover\(=[0-9A-Za-z,_-]*\)*//)
             save_CXXFLAGS=$CXXFLAGS
             CXXFLAGS="$CXXFLAGS $KDE4_CFLAGS"
             save_LIBS=$LIBS