Add riscv

Signed-off-by: Guillaume J. Charmes <guillaume@charmes.net>

test_crosscompile.sh

@@ -45,7 +45,6 @@ if ! hash docker; then
     return
 fi
 
-#linux/riscv # Should work once we merge #81.
-#echo2 "Build for linux."
-#echo2 "  - linux/riscv"
-#docker build -t test -f Dockerfile.riscv .
+echo2 "Build for linux."
+echo2 "  - linux/riscv"
+docker build -t test -f Dockerfile.riscv .

ztypes_riscvx.go

@@ -1,7 +1,7 @@
 // Code generated by cmd/cgo -godefs; DO NOT EDIT.
 // cgo -godefs types.go
 
-// +build riscv64
+// +build riscv riscv64
 
 package pty