[libc][stdfix] Re-enable fixed point abs entry points. (#81995)

#80757 has been merged.

Author: lntue

libc/config/linux/x86_64/entrypoints.txt

@@ -445,13 +445,12 @@ endif()
 if(LIBC_COMPILER_HAS_FIXED_POINT)
   list(APPEND TARGET_LIBM_ENTRYPOINTS
     # stdfix.h _Fract and _Accum entrypoints
-    # Re-enable the entry points once #80757 is merged.
-    # libc.src.stdfix.abshk
-    # libc.src.stdfix.abshr
-    # libc.src.stdfix.absk
-    # libc.src.stdfix.absr
-    # libc.src.stdfix.abslk
-    # libc.src.stdfix.abslr
+    libc.src.stdfix.abshk
+    libc.src.stdfix.abshr
+    libc.src.stdfix.absk
+    libc.src.stdfix.absr
+    libc.src.stdfix.abslk
+    libc.src.stdfix.abslr
   )
 endif()