Supress line noise.

src/cmd/rc/.cvsignore

diff --git a/src/cmd/rc/.cvsignore b/src/cmd/rc/.cvsignore
new file mode 100644
index 0000000..abdaeea
--- /dev/null
+++ b/src/cmd/rc/.cvsignore
@@ -0,0 +1,3 @@
+x.tab.h
+y.tab.c
+y.tab.h

src/cmd/tbl/.cvsignore

diff --git a/src/cmd/tbl/.cvsignore b/src/cmd/tbl/.cvsignore
new file mode 100644
index 0000000..9483a3f
--- /dev/null
+++ b/src/cmd/tbl/.cvsignore
@@ -0,0 +1 @@
+o.trbl

src/cmd/troff/.cvsignore

diff --git a/src/cmd/troff/.cvsignore b/src/cmd/troff/.cvsignore
new file mode 100644
index 0000000..6b401b1
--- /dev/null
+++ b/src/cmd/troff/.cvsignore
@@ -0,0 +1 @@
+o.troff