Improve parsing error for static and const

Example
---
```rust
static C<i32>: u32 = 0;
```
->
```diff
-error 8: missing type for `const` or `static`
+error 8: `static` may not have generic parameters
```

---

```rust
const C = 0;
```
->
```diff
-error 7: missing type for `const` or `static`
+error 7: missing type for `const`
```

---

```rust
static C = 0;
```
->
```diff
-error 8: missing type for `const` or `static`
+error 8: missing type for `static`
```

crates/parser/src/grammar/items/consts.rs

@@ -32,14 +32,22 @@ fn const_or_static(p: &mut Parser<'_>, m: Marker, is_const: bool) {
         //     const C<'a>: &'a () = &();
         // }
         generic_params::opt_generic_param_list(p);
+    } else if p.at(T![<]) {
+        p.error("`static` may not have generic parameters");
     }
     // test_err generic_static
     // static C<i32>: u32 = 0;
 
     if p.at(T![:]) {
         types::ascription(p);
-    } else {
+    } else if is_const {
-        p.error("missing type for `const` or `static`");
+        // test_err missing_const_type
+        // const C = 0;
+        p.error("missing type for `const`");
+    } else if !p.at(T![<]) {
+        // test_err missing_static_type
+        // static C = 0;
+        p.error("missing type for `static`");
     }
     if p.eat(T![=]) {
         expressions::expr(p);

crates/parser/test_data/generated/runner.rs

@@ -824,10 +824,18 @@ mod err {
         run_and_expect_errors("test_data/parser/inline/err/misplaced_label_err.rs");
     }
     #[test]
+    fn missing_const_type() {
+        run_and_expect_errors("test_data/parser/inline/err/missing_const_type.rs");
+    }
+    #[test]
     fn missing_fn_param_type() {
         run_and_expect_errors("test_data/parser/inline/err/missing_fn_param_type.rs");
     }
     #[test]
+    fn missing_static_type() {
+        run_and_expect_errors("test_data/parser/inline/err/missing_static_type.rs");
+    }
+    #[test]
     fn path_item_without_excl() {
         run_and_expect_errors("test_data/parser/inline/err/path_item_without_excl.rs");
     }

crates/parser/test_data/parser/err/0044_item_modifiers.rast

@@ -42,7 +42,7 @@ SOURCE_FILE
   WHITESPACE "\n"
 error 6: expected fn, trait or impl
 error 38: expected a name
-error 40: missing type for `const` or `static`
+error 40: missing type for `const`
 error 40: expected SEMICOLON
 error 44: expected an item
 error 44: expected an item

crates/parser/test_data/parser/inline/err/generic_static.rast

@@ -30,7 +30,7 @@ SOURCE_FILE
   ERROR
     SEMICOLON ";"
   WHITESPACE "\n"
-error 8: missing type for `const` or `static`
+error 8: `static` may not have generic parameters
 error 8: expected SEMICOLON
 error 8: expected an item
 error 12: expected an item

crates/parser/test_data/parser/inline/err/missing_const_type.rast

@@ -0,0 +1,14 @@
+SOURCE_FILE
+  CONST
+    CONST_KW "const"
+    WHITESPACE " "
+    NAME
+      IDENT "C"
+    WHITESPACE " "
+    EQ "="
+    WHITESPACE " "
+    LITERAL
+      INT_NUMBER "0"
+    SEMICOLON ";"
+  WHITESPACE "\n"
+error 7: missing type for `const`

crates/parser/test_data/parser/inline/err/missing_const_type.rs

@@ -0,0 +1 @@
+const C = 0;

crates/parser/test_data/parser/inline/err/missing_static_type.rast

@@ -0,0 +1,14 @@
+SOURCE_FILE
+  STATIC
+    STATIC_KW "static"
+    WHITESPACE " "
+    NAME
+      IDENT "C"
+    WHITESPACE " "
+    EQ "="
+    WHITESPACE " "
+    LITERAL
+      INT_NUMBER "0"
+    SEMICOLON ";"
+  WHITESPACE "\n"
+error 8: missing type for `static`

crates/parser/test_data/parser/inline/err/missing_static_type.rs

@@ -0,0 +1 @@
+static C = 0;