fixup! [Clang] Attribute NoFPClass should not prevent tail call optimization.

Improved test

Author: felix642

llvm/test/CodeGen/X86/tailcall-nofpclass.ll

@@ -1,10 +1,13 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
 ; RUN: llc -mtriple=x86_64-linux < %s | FileCheck %s
 
-define dso_local noundef nofpclass(nan inf) float @_Z3foof(float noundef nofpclass(nan inf) %0) {
+; Ensures that taillcall optimization can still be
+; performed when nofpclass is used.
+
+define noundef nofpclass(nan inf) float @_Z3foof(float noundef nofpclass(nan inf) %0) {
 ; CHECK-LABEL: _Z3foof:
 ; CHECK:       # %bb.0:
 ; CHECK-NEXT:    jmp expf@PLT # TAILCALL
-  %2 = tail call fast float @llvm.exp.f32(float %0)
+  %2 = tail call float @llvm.exp.f32(float %0)
   ret float %2
 }