[flang][test] Fix test REQUIRES and options for aint.f90 (#146870)

This test should have been looking for the "x86" target, not "x86_64".

In the time it's not been running, -target must have been changed to
-triple.

Author: DavidSpickett

flang/test/Lower/math-lowering/aint.f90

@@ -1,10 +1,10 @@
-! REQUIRES: x86_64-registered-target
+! REQUIRES: x86-registered-target
 ! RUN: bbc -target x86_64-unknown-linux-gnu -emit-fir %s -o - --math-runtime=fast | FileCheck --check-prefixes=ALL %s
-! RUN: %flang_fc1 -target x86_64-unknown-linux-gnu -emit-fir -mllvm -math-runtime=fast %s -o - | FileCheck --check-prefixes=ALL %s
+! RUN: %flang_fc1 -triple x86_64-unknown-linux-gnu -emit-fir -mllvm -math-runtime=fast %s -o - | FileCheck --check-prefixes=ALL %s
 ! RUN: bbc -target x86_64-unknown-linux-gnu -emit-fir %s -o - --math-runtime=relaxed | FileCheck --check-prefixes=ALL %s
-! RUN: %flang_fc1 -target x86_64-unknown-linux-gnu -emit-fir -mllvm -math-runtime=relaxed %s -o - | FileCheck --check-prefixes=ALL %s
+! RUN: %flang_fc1 -triple x86_64-unknown-linux-gnu -emit-fir -mllvm -math-runtime=relaxed %s -o - | FileCheck --check-prefixes=ALL %s
 ! RUN: bbc -target x86_64-unknown-linux-gnu -emit-fir %s -o - --math-runtime=precise | FileCheck --check-prefixes=ALL %s
-! RUN: %flang_fc1 -target x86_64-unknown-linux-gnu -emit-fir -mllvm -math-runtime=precise %s -o - | FileCheck --check-prefixes=ALL %s
+! RUN: %flang_fc1 -triple x86_64-unknown-linux-gnu -emit-fir -mllvm -math-runtime=precise %s -o - | FileCheck --check-prefixes=ALL %s
 
 function test_real4(x)
   real :: x, test_real4