[flang][cuda] Add bind name for __clz interface (#153268)

Author: clementval

flang/module/cudadevice.f90

@@ -738,11 +738,11 @@ attributes(device) real(8) function sinpi(x) bind(c,name='__nv_sinpi')
   end interface
 
   interface __clz
-    attributes(device) integer function __clz(i) bind(c)
+    attributes(device) integer function __clz(i) bind(c, name='__nv_clz')
       !dir$ ignore_tkr (d) i
       integer, value :: i
     end function
-    attributes(device) integer function __clzll(i) bind(c)
+    attributes(device) integer function __clzll(i) bind(c, name='__nv_clzll')
       !dir$ ignore_tkr (d) i
       integer(8), value :: i
     end function

flang/test/Lower/CUDA/cuda-device-proc.cuf

@@ -58,7 +58,8 @@ attributes(global) subroutine devsub()
   res = __ffs(al)
   res = __brev(ai)
   resl = __brev(al)
-
+  res = __clz(ai)
+  res = __clz(al)
   ai = __mul24(ai, ai)
   ai = __umul24(ai, ai)
 end
@@ -107,6 +108,8 @@ end
 ! CHECK: %{{.*}} = fir.call @__nv_ffsll(%{{.*}}) proc_attrs<bind_c> fastmath<contract> : (i64) -> i32
 ! CHECK: %{{.*}} = fir.call @__nv_brev(%{{.*}}) proc_attrs<bind_c> fastmath<contract> : (i32) -> i32
 ! CHECK: %{{.*}} = fir.call @__nv_brevll(%{{.*}}) proc_attrs<bind_c> fastmath<contract> : (i64) -> i64
+! CHECK: %{{.*}} = fir.call @__nv_clz(%{{.*}}) proc_attrs<bind_c> fastmath<contract> : (i32) -> i32
+! CHECK: %{{.*}} = fir.call @__nv_clzll(%{{.*}}) proc_attrs<bind_c> fastmath<contract> : (i64) -> i32
 
 ! CHECK: %{{.*}} = fir.call @__nv_mul24(%{{.*}}, %{{.*}}) proc_attrs<bind_c> fastmath<contract> : (i32, i32) -> i32
 ! CHECK: %{{.*}} = fir.call @__nv_umul24(%{{.*}}, %{{.*}}) proc_attrs<bind_c> fastmath<contract> : (i32, i32) -> i32