Import error corpus entries from grammar repos

Now that error recovery requires no input for the grammar author, it shouldn't
be tested in the individual grammar repos.

spec/fixtures/error_corpus/c_errors.txt

@@ -0,0 +1,94 @@
+========================================
+Errors inside ifdefs
+========================================
+
+#ifdef something
+int x // no semicolon
+#endif
+
+int a;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int b;
+
+#ifdef __cplusplus
+}
+#endif
+
+int c;
+
+---
+
+(translation_unit
+  (preproc_ifdef
+    (identifier)
+    (ERROR (identifier) (identifier) (comment)))
+
+  (declaration (identifier) (identifier))
+
+  (preproc_ifdef
+    (identifier)
+    (ERROR (storage_class_specifier) (string_literal)))
+
+  (declaration (identifier) (identifier))
+
+  (preproc_ifdef
+    (identifier)
+    (ERROR))
+
+  (declaration (identifier) (identifier)))
+
+========================================
+Errors inside blocks
+========================================
+
+int main() {
+  int x;
+  int %$#@
+}
+
+---
+
+(translation_unit
+  (function_definition
+    (identifier)
+    (function_declarator (identifier))
+    (compound_statement
+      (declaration (identifier) (identifier))
+      (ERROR (identifier) (UNEXPECTED '$')))))
+
+========================================
+Errors inside expressions
+========================================
+
+int main() {
+  int x = (123 123);
+}
+
+---
+
+(translation_unit
+  (function_definition
+    (identifier)
+    (function_declarator (identifier))
+    (compound_statement
+      (declaration (identifier) (init_declarator
+        (identifier)
+        (ERROR (number_literal))
+        (number_literal))))))
+
+========================================
+Errors in declarations
+========================================
+
+float x WTF;
+int y = 5;
+
+---
+
+(translation_unit
+  (declaration (identifier) (identifier) (ERROR (identifier)))
+  (declaration (identifier) (init_declarator (identifier) (number_literal))))

spec/fixtures/error_corpus/javascript_errors.txt

@@ -0,0 +1,127 @@
+============================================
+Invalid statements
+============================================
+
+what the heck !
+y();
+
+if (x) {
+  >>>
+  var y = right
+}
+
+---
+
+(program
+  (expression_statement
+    (identifier)
+    (ERROR (identifier) (identifier)))
+  (expression_statement (function_call (identifier)))
+  (if_statement (identifier) (statement_block
+    (ERROR)
+    (var_declaration (var_assignment (identifier) (identifier))))))
+
+============================================
+Invalid if conditions
+============================================
+
+if (uh oh)
+  hmm();
+
+ok();
+
+---
+
+(program
+  (if_statement (identifier) (ERROR (identifier))
+    (expression_statement (function_call (identifier))))
+  (expression_statement (function_call (identifier))))
+
+============================================
+Invalid for loops
+============================================
+
+ok1;
+
+for (a b c; d; e)
+  wat();
+
+ok2;
+
+for (a; b; c d ef)
+  wat();
+
+---
+
+(program
+  (expression_statement (identifier))
+
+  (for_statement
+    (ERROR (identifier) (identifier))
+    (identifier)
+    (identifier)
+    (identifier)
+    (expression_statement (function_call (identifier))))
+
+  (expression_statement (identifier))
+
+  (for_statement
+    (identifier)
+    (identifier)
+    (ERROR (identifier) (identifier))
+    (identifier)
+    (expression_statement (function_call (identifier)))))
+
+============================================
+Invalid statement blocks
+============================================
+
+function() { ^ & * }
+
+---
+
+(program
+  (expression_statement (function (statement_block (ERROR)))))
+
+============================================
+Invalid objects
+============================================
+
+x = {
+  key1: value1,
+
+  abc efg,
+
+  key2: value2
+};
+
+---
+
+(program
+  (expression_statement (assignment
+    (identifier)
+    (object
+      (pair (identifier) (identifier))
+      (ERROR (identifier) (identifier))
+      (pair (identifier) (identifier))))))
+
+============================================
+Invalid items in var declarations
+============================================
+
+var
+  a = 1,
+  -b,
+  c = 2,
+  d = = = = =,
+  e;
+
+---
+
+(program
+  (var_declaration
+    (var_assignment (identifier) (number))
+    (ERROR (UNEXPECTED '-') (identifier))
+    (var_assignment (identifier) (number))
+    (ERROR (identifier) (UNEXPECTED '='))
+    (identifier)))

spec/fixtures/error_corpus/json_errors.txt

@@ -0,0 +1,56 @@
+==========================================
+top-level errors
+==========================================
+
+[}
+
+---
+
+(ERROR)
+
+==========================================
+unexpected tokens
+==========================================
+
+barf
+
+---
+
+(ERROR (UNEXPECTED 'b'))
+
+==========================================
+errors inside arrays
+==========================================
+
+[1, , 2]
+
+---
+(array
+  (number)
+  (ERROR)
+  (number))
+
+==========================================
+errors inside objects
+==========================================
+
+{ "key1": 1, oops }
+
+---
+
+(object (pair (string) (number)) (ERROR (UNEXPECTED 'o')))
+
+==========================================
+errors inside nested objects
+==========================================
+
+{ "key1": { "key2": 1, 2 }, [, "key3": 3 }
+
+---
+
+(object
+  (pair (string) (object
+    (pair (string) (number))
+    (ERROR (number))))
+  (ERROR)
+  (pair (string) (number)))