update elements and fix some bugs

lib/src/prism/tests/languages/c/keyword_feature.test

Index: lib/src/prism/tests/languages/c/keyword_feature.test
diff --git a/lib/src/prism/tests/languages/c/keyword_feature.test b/lib/src/prism/tests/languages/c/keyword_feature.test
new file mode 100644
index 0000000000000000000000000000000000000000..3c9f6e01c64363f20666f8d4f43803a346c72195
--- /dev/null
+++ b/lib/src/prism/tests/languages/c/keyword_feature.test
@@ -0,0 +1,23 @@
+asm typeof inline auto break
+case char const continue default
+do double else enum extern
+float for goto if int
+long register return short signed
+sizeof static struct switch typedef
+union unsigned void volatile while
+
+----------------------------------------------------
+
+[
+	["keyword", "asm"], ["keyword", "typeof"], ["keyword", "inline"], ["keyword", "auto"], ["keyword", "break"],
+	["keyword", "case"], ["keyword", "char"], ["keyword", "const"], ["keyword", "continue"], ["keyword", "default"],
+	["keyword", "do"], ["keyword", "double"], ["keyword", "else"], ["keyword", "enum"], ["keyword", "extern"],
+	["keyword", "float"], ["keyword", "for"], ["keyword", "goto"], ["keyword", "if"], ["keyword", "int"],
+	["keyword", "long"], ["keyword", "register"], ["keyword", "return"], ["keyword", "short"], ["keyword", "signed"],
+	["keyword", "sizeof"], ["keyword", "static"], ["keyword", "struct"], ["keyword", "switch"], ["keyword", "typedef"],
+	["keyword", "union"], ["keyword", "unsigned"], ["keyword", "void"], ["keyword", "volatile"], ["keyword", "while"]
+]
+
+----------------------------------------------------
+
+Checks for all keywords.