Fix (thread-start!) to return thread obj, per SRFI 18

CHANGELOG.md

@@ -12,7 +12,8 @@ Bug Fixes
 - Properly handle vectors literals at the top level of compiled code. Previously this could lead to segmentation faults (!!) at runtime.
 - Fixed a bug in `make-list` that consumed all available memory when passing a negative list length.
 - Allow a record type to contain fields that are not initialized by the constructor.
-- Fix off-by-one error unpacking arguments when calling a primitive as the continuation after a garbage collection.
+- Fixed an off-by-one error unpacking arguments when calling a primitive as the continuation after a garbage collection.
+- Updated `thread-start!` to return the given thread object, per SRFI 18.
 
 Bug Fixes for C Compiler Warnings
 

srfi/18.sld

@@ -127,7 +127,7 @@
                                              ;; data available for child init
         (Cyc-minor-gc)
         (Cyc-spawn-thread! thread-params)
-        ))
+        t))
 
     (define (thread-yield!) (thread-sleep! 1))
     (define-c thread-terminate!