flang2: fix the expected number of parameters for __pd_asin_1

This bug was hidden unnoticed for years, until the most recent
changes in LLVM (LLVM-18 candidate) have introduced additional
assertions in the loop vectorizer, and one of them is failing
on wrongly declared functions like this one.

Signed-off-by: Paul Osmialowski <pawel.osmialowski@arm.com>

tools/flang2/flang2exe/iliutil.cpp

@@ -6134,7 +6134,7 @@ addarth(ILI *ilip)
 
   case IL_DASIN:
     if (XBIT_NEW_MATH_NAMES) {
-      fname = make_math(MTH_asin, &funcsptr, 1, false, DT_DBLE, 2, DT_DBLE,
+      fname = make_math(MTH_asin, &funcsptr, 1, false, DT_DBLE, 1, DT_DBLE,
                         DT_DBLE);
       ilix = ad_func(IL_dpfunc, IL_QJSR, fname, 1, op1);
       ilix = ad1altili(opc, op1, ilix);