runtime: performance regression due to bad instruction used in morestack_noctxt for ppc64 in CL 425396 [1.19 backport]

[gopherbot]

@archanaravindar requested issue #57741 to be considered for backport to the next 1.19 minor release.

@gopherbot please backport this to previous releases Go1.19 and Go1.18
Since the fix 54332 that causes this regression on ppc64 has been likewise back ported to these two releases

[archanaravindar]

Since the fix removes the regression in Go1.19 for the following benchmarks, we request this issue to be back ported

StackCopyPtr-64 138ms           85ms%   -38.36% 
StackCopy-64    137ms           83ms%   -39.48% 
StackCopyNoCache-64     15.1ms  2.5ms   -83.49% 
StackCopyWithStkobj-64  39.9ms  14.4ms  -63.89% 
                                                                        
Hash65536-64    23.5µs          3.9µs   -83.28% 
MegEqMap-64     146µs           22µs    -84.63% 
RepeatedLookupStrMapKey1M-64    403µs   63µs    -84.45% 
MakeChan/Struct/40-64   197ns   146ns   -25.83% 
GoMapClear/NonReflexive/10000-64        116µs   18µs    -84.79% 
MapPop10000-64  9.44ms          4.09ms  -56.72% 

[gopherbot]

Change https://go.dev/cl/462335 mentions this issue: [release-branch.go1.19] runtime: fix performance regression in morestack_noctxt on ppc64

[gopherbot]

Closed by merging 73e1aff to release-branch.go1.19.