[flang][test] Restrict Evaluate/fold-out_of_range.f90 to x86_64 (#102890)

`Flang :: Evaluate/fold-out_of_range.f90` currently `FAIL`s on
Linux/sparc64. This seems to be the same issue that led to disabling the
test on Solaris in 27549ee. In fact,
the generic Solaris disablement was over-eager: the test `PASS`es just
fine on Solaris/amd64.

Since the use of `REAL*10` makes the test x86-specific, this patch
actually implements that requirement.

Tested on `sparc64-unknown-linux-gnu`, `sparcv9-sun-solaris2.11`,
`amd64-pc-solaris2.11`, and `x86_64-pc-linux-gnu`.

Author: rorth

flang/test/Evaluate/fold-out_of_range.f90

@@ -1,5 +1,6 @@
-! RUN: %python %S/test_folding.py %s %flang_fc1 -pedantic
-! UNSUPPORTED: target=powerpc{{.*}}, target=aarch{{.*}}, target=arm{{.*}}, system-windows, system-solaris
+! RUN: %python %S/test_folding.py %s %flang_fc1 -pedantic -triple x86_64-unknown-linux-gnu
+! UNSUPPORTED: system-windows
+! REQUIRES: target=x86_64{{.*}}
 ! Tests folding of OUT_OF_RANGE().
 module m
   integer(1),  parameter :: i1v(*)  = [ -huge(1_1)  - 1_1,  huge(1_1) ]