shell: add a few yet-failing arithmentic tests

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

shell/ash_test/ash-arith/arith-assign-in-varexp.right

@@ -0,0 +1,3 @@
+20:20
+a=b=10
+b=10

shell/ash_test/ash-arith/arith-assign-in-varexp.tests

@@ -0,0 +1,8 @@
+exec 2>&1
+a='b=10'
+b=3
+# The variables should evaluate left-to-right,
+# thus b is set to 10 _before_ addition
+echo 20:$((a + b))
+echo "a=$a"
+echo "b=$b"

shell/ash_test/ash-arith/arith-comma1.right

@@ -0,0 +1,3 @@
+10:10
+a=b=10
+b=10

shell/ash_test/ash-arith/arith-comma1.tests

@@ -0,0 +1,6 @@
+exec 2>&1
+a='b=10'
+b=3
+echo 10:$((a,b))
+echo "a=$a"
+echo "b=$b"

shell/ash_test/ash-arith/arith-precedence1.right

@@ -0,0 +1 @@
+4:4

shell/ash_test/ash-arith/arith-precedence1.tests

@@ -0,0 +1,2 @@
+exec 2>&1
+echo 4:"$((0 ? 1,2 : 3,4))"

shell/ash_test/ash-arith/arith-ternary1.right

@@ -0,0 +1,5 @@
+42:42
+a=0
+6:6
+a=b=+err+
+b=6

shell/ash_test/ash-arith/arith-ternary1.tests

@@ -0,0 +1,12 @@
+exec 2>&1
+a=0
+# The not-taken branch should not evaluate
+echo 42:$((1 ? 42 : (a+=2)))
+echo "a=$a"
+
+a='b=+err+'
+b=5
+# The not-taken branch should not even parse variables
+echo 6:$((0 ? a : ++b))
+echo "a=$a"
+echo "b=$b"

shell/ash_test/ash-arith/arith-ternary2.right

@@ -0,0 +1 @@
+5:5

shell/ash_test/ash-arith/arith-ternary2.tests

@@ -0,0 +1,2 @@
+exec 2>&1
+echo 5:$((1?2?3?4?5:6:7:8:9))