Better fix

Detail:
  AcquireMutex doesn't have the same functionality as Arm2Swp, best not to
  make people think they might do. Also add an extra literal pool because
  otherwise some instructions don't reach when doing APCS-32 softload builds.

Retagged as 'RISC_OSLib-5_88'

kernel/s/k_body

@@ -103,7 +103,9 @@
         EXPORT  |x$uremainder|
 
         EXPORT  |__counter|
+ [ {CONFIG}<>26
         EXPORT  |AcquireMutex|
+ ]
 
 PSRBits         *       &FC000003
 PSRZBit         *       &40000000
@@ -3065,10 +3067,10 @@ StackOverflowFault Keep
         BL      |_kernel_copyerror|
         SWI     GenerateError
 
+        LTORG
         ErrorBlock StackOverflow, "Stack overflow", C45
 
  [ {CONFIG}=26
-AcquireMutex
 Arm2Swp ; like SWP a1,a1,[a2] but corrupts a3, lr and flags
         SWI     IntOff
         LDR     a3, [a2]