Include files in the directory of src

mpact_isa_decoder() and mpact_bin_fmt_decoder() uses the working
directory to find files to include, but it is unreliable the working
directory will vary if the repository containing the source files is
nested.

To avoid this unreliability, always include files in the directory of
src.

mpact/sim/decoder/mpact_sim_isa.bzl

diff --git a/mpact/sim/decoder/mpact_sim_isa.bzl b/mpact/sim/decoder/mpact_sim_isa.bzl
index 668817b..e8dacc6 100644
--- a/mpact/sim/decoder/mpact_sim_isa.bzl
+++ b/mpact/sim/decoder/mpact_sim_isa.bzl
@@ -273,7 +273,7 @@
     # Add the sources that are not in includes.
     for i in range(0, num_srcs):
         cmd += "$${ARR[" + str(i) + "]} "
-    cmd += "--prefix " + prefix + " --output_dir $(@D)"
+    cmd += "--prefix " + prefix + " --output_dir $(@D) --include $$(dirname $${ARR[0]})"
     if isa_name != "":
         cmd += " --isa_name " + isa_name
 
@@ -288,7 +288,7 @@
     # Add the sources that are not in includes.
     for i in range(0, num_srcs):
         cmd += "$${ARR[" + str(i) + "]} "
-    cmd += " --prefix " + prefix + " --output_dir $(@D)"
+    cmd += " --prefix " + prefix + " --output_dir $(@D) --include $$(dirname $${ARR[0]})"
     if decoder_name != "":
         cmd += " --decoder_name " + decoder_name
     return cmd