Don't use the bazel toolchain to link against libllvm

Managing versions and standard libraries to keep these compatible is
annoying, so just use a shell script to compile this one file.

Change-Id: I6167b9c6cc5395430be1ce9964dea4c1b1e6f3ad
Signed-off-by: Brian Silverman <bsilver16834@gmail.com>
diff --git a/debian/halide.BUILD b/debian/halide.BUILD
index fc43fd0..972df97 100644
--- a/debian/halide.BUILD
+++ b/debian/halide.BUILD
@@ -24,3 +24,12 @@
     includes = ["include"],
     visibility = ["//visibility:public"],
 )
+
+filegroup(
+    name = "build_files",
+    srcs = [
+        "lib/libHalide.a",
+        "tools/GenGen.cpp",
+    ] + glob(["include/*.h"]),
+    visibility = ["//visibility:public"],
+)