Merge commit '59b9d2f6'

* commit '59b9d2f6':
  configure: Add support for clang llvm-cov

Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

configure

@@ -3467,6 +3467,10 @@ case "$toolchain" in
         add_cflags  -fprofile-arcs -ftest-coverage
         add_ldflags -fprofile-arcs -ftest-coverage
     ;;
+    llvm-cov)
+        add_cflags -fprofile-arcs -ftest-coverage
+        add_ldflags --coverage
+    ;;
     hardened)
         add_cppflags -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2
         add_cflags   -fno-strict-overflow -fstack-protector-all