runtime: for Solaris, add osinit, and drop duplicate getncpu

Fixes a build breakage introduced in the 1.14beta1 upgrade.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/215857

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-9ae2223f91c4ca642885b80d88eb0baf756acf94
+1d64b76f559c0969ee2a6eb8e0ac9d268713880c
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/go/runtime/os3_solaris.go

@@ -17,12 +17,11 @@ func getPageSize() int32
 //extern sysconf
 func sysconf(int32) _C_long
 
-func getncpu() int32 {
-	n := int32(sysconf(__SC_NPROCESSORS_ONLN))
-	if n < 1 {
-		return 1
+func osinit() {
+	ncpu = getncpu()
+	if physPageSize == 0 {
+		physPageSize = uintptr(getPageSize())
 	}
-	return n
 }
 
 func sysargs(argc int32, argv **byte) {