Add spec/syntax_spec.cr (#16749)

A handy spec entry point that run all specs related to syntax (parsing, formatting, tools).

Author: straight-shoota

spec/syntax_spec.cr

@@ -0,0 +1,12 @@
+# This is a spec entry point to run all specs related to syntax (parsing, formatting, tools).
+
+require "./compiler/lexer/**"
+require "./compiler/parser/**"
+require "./compiler/formatter/**"
+
+require "./compiler/crystal/tools/doc_spec.cr"
+require "./compiler/crystal/tools/doc/**"
+require "./compiler/crystal/tools/flags_spec.cr"
+require "./compiler/crystal/tools/format_spec.cr"
+
+require "./std/crystal/syntax_highlighter/**"