internal/cpu: do not require POWER8

Although the gc toolchain requires POWER8, the gccgo toolchain does not.

Fixes https://gcc.gnu.org/PR89169

Change-Id: Iecc6fe48b705a73322ad75923868281d2a303d64
Reviewed-on: https://go-review.googlesource.com/c/162979
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
diff --git a/libgo/go/internal/cpu/cpu_ppc64x.go b/libgo/go/internal/cpu/cpu_ppc64x.go
index c59503f..02f2c06 100644
--- a/libgo/go/internal/cpu/cpu_ppc64x.go
+++ b/libgo/go/internal/cpu/cpu_ppc64x.go
@@ -29,9 +29,7 @@
 		{Name: "darn", Feature: &PPC64.HasDARN},
 		{Name: "scv", Feature: &PPC64.HasSCV},
 		{Name: "power9", Feature: &PPC64.IsPOWER9},
-
-		// These capabilities should always be enabled on ppc64 and ppc64le:
-		{Name: "power8", Feature: &PPC64.IsPOWER8, Required: true},
+		{Name: "power8", Feature: &PPC64.IsPOWER8},
 	}
 
 	// HWCAP2 feature bits