Don't suppress reading record and custom data reader types (#948)

Fixes #947

Author: chrisrink10

CHANGELOG.md

@@ -26,6 +26,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  * Fix a bug where `basilisp.lang.seq.LazySeq` instances were not thread-safe (#934)
  * Fix a bug where Seqs wrapping Python Iterable instances were not thread-safe (#936)
  * Fix several bugs where code was being executed from a string with interpolated variables, which could've allowed for code (#938)
+ * Fix a bug where record types and data readers whose fully qualified name started with a "b" could not be read (#947)
 
 ### Other
  * Add several sections to Concepts documentation module (#666)

src/basilisp/lang/reader.py

@@ -1547,12 +1547,12 @@ def _read_reader_macro(ctx: ReaderContext) -> LispReaderForm:  # noqa: MC0001
             raise ctx.syntax_error(e.message).with_traceback(e.__traceback__) from None
     elif char == "#":
         return _read_numeric_constant(ctx)
-    elif char == "b":
-        ctx.reader.advance()
-        return _read_byte_str(ctx)
     elif ns_name_chars.match(char):
         s = _read_sym(ctx)
         assert isinstance(s, sym.Symbol)
+        if s.ns is None and s.name == "b":
+            return _read_byte_str(ctx)
+
         v = _read_next_consuming_comment(ctx)
         if s in ctx.data_readers:
             f = ctx.data_readers[s]