Fix language tests a bit

- Remove some stray saved error messages that didn't correspond to any
  test, because they were renamed in
  d11faa01b5.

- Need `--eval` in test failure test in order to get in "read-only" mode
  where we don't try to write to the store. (The other tests already do
  this.)

- Need `--strict` so top-level attribute sets are still forced, like
  they are without `--eval`.

tests/functional/lang.sh

@@ -68,7 +68,7 @@ for i in lang/eval-fail-*.nix; do
     echo "evaluating $i (should fail)";
     i=$(basename "$i" .nix)
     if
-        expectStderr 1 nix-instantiate --show-trace "lang/$i.nix" \
+        expectStderr 1 nix-instantiate --eval --strict --show-trace "lang/$i.nix" \
             | sed "s!$(pwd)!/pwd!g" > "lang/$i.err"
     then
         diffAndAccept "$i" err err.exp

tests/functional/lang/eval-fail-antiquoted-path.err.exp

@@ -1 +0,0 @@
-error: getting attributes of path ‘PWD/lang/fnord’: No such file or directory

tests/functional/lang/eval-fail-bad-antiquote-1.err.exp

@@ -1,10 +0,0 @@
-error:
-       … while evaluating a path segment
-
-         at /pwd/lang/eval-fail-bad-antiquote-1.nix:1:2:
-
-            1| "${x: x}"
-             |  ^
-            2|
-
-       error: cannot coerce a function to a string

tests/functional/lang/eval-fail-bad-antiquote-2.err.exp

@@ -1 +0,0 @@
-error: operation 'addToStoreFromDump' is not supported by store 'dummy'

tests/functional/lang/eval-fail-bad-antiquote-3.err.exp

@@ -1,10 +0,0 @@
-error:
-       … while evaluating a path segment
-
-         at /pwd/lang/eval-fail-bad-antiquote-3.nix:1:3:
-
-            1| ''${x: x}''
-             |   ^
-            2|
-
-       error: cannot coerce a function to a string

tests/functional/lang/eval-fail-bad-string-interpolation-2.err.exp

@@ -1 +1 @@
-error: operation 'addToStoreFromDump' is not supported by store 'dummy'
+error: getting status of '/pwd/lang/fnord': No such file or directory

tests/functional/lang/eval-fail-dup-dynamic-attrs.err.exp

@@ -1,4 +1,14 @@
-error: dynamic attribute 'b' already defined at /pwd/lang/eval-fail-dup-dynamic-attrs.nix:2:11
+error:
+       … while evaluating the attribute 'set'
+
+         at /pwd/lang/eval-fail-dup-dynamic-attrs.nix:2:3:
+
+            1| {
+            2|   set = { "${"" + "b"}" = 1; };
+             |   ^
+            3|   set = { "${"b" + ""}" = 2; };
+
+       error: dynamic attribute 'b' already defined at /pwd/lang/eval-fail-dup-dynamic-attrs.nix:2:11
 
        at /pwd/lang/eval-fail-dup-dynamic-attrs.nix:3:11:
 

tests/functional/lang/eval-fail-nonexist-path.err.exp

@@ -1 +1 @@
-error: operation 'addToStoreFromDump' is not supported by store 'dummy'
+error: getting status of '/pwd/lang/fnord': No such file or directory

tests/functional/lang/parse-fail-dup-attrs-6.err.exp

@@ -1 +0,0 @@
-error: attribute ‘services.ssh’ at (string):3:3 already defined at (string):2:3