[flang][test] Fix Lower/default-initialization-globals.f90 on SPARC (#103722)

`Flang :: Lower/default-initialization-globals.f90` `FAIL`s on SPARC,
both Solaris/sparcv9 and Linux/sparc64.

The failure mode is same as on AIX/PowerPC, so both targets being
big-endian, this patch treats them the same.

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

Author: rorth

flang/test/Lower/default-initialization-globals.f90

@@ -1,5 +1,5 @@
 ! Test default initialization of global variables (static init)
-! RUN: bbc -hlfir=false %s -o - | FileCheck %s --check-prefixes=%if system-aix %{"CHECK","CHECK-BE"%} \
+! RUN: bbc -hlfir=false %s -o - | FileCheck %s --check-prefixes=%if target={{.*-aix.*|sparc.*}} %{"CHECK","CHECK-BE"%} \
 ! RUN:                                         %else %{"CHECK","CHECK-LE"%}
 
 module tinit