[NFC][libc++][libc++abi][libunwind][test] Fix/unify AIX triples used in LIT tests (#101196)

This patch fixes/unifies AIX target triples used in libc++, libc++abi,
and libunwind LIT tests.

NOKEYCHECK=True
GitOrigin-RevId: 2d3655037ccfa276cb0949c2ce0cff56985f6637

Author: xingxue-ibm

test/libcxx/vendor/ibm/bad_function_call.pass.cpp

@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// REQUIRES: target={{powerpc.*-ibm-aix.*}}
+// REQUIRES: target={{.+}}-aix{{.*}}
 // ADDITIONAL_COMPILE_FLAGS: -fvisibility-inlines-hidden
 
 // When there is a weak hidden symbol in user code and a strong definition