[libc++][Android] strong_order_long_double.verify.cpp: disable on i686

This target (as well as 32-bit ARM Android) have sizeof(long double)
equal to sizeof(double).

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D137135

Author: rprichard

libcxx/test/std/language.support/cmp/cmp.alg/strong_order_long_double.verify.cpp

@@ -17,6 +17,8 @@
 // ARM/AArch64 MinGW also has got long double equal to regular double, just
 // like MSVC (thus match both MinGW and MSVC here, for those architectures).
 // UNSUPPORTED: target={{aarch64|armv7}}-{{.*}}-windows-{{.+}}
+// Android's 32-bit x86 target has long double equal to regular double.
+// UNSUPPORTED: target=i686-{{.+}}-android{{.*}}
 
 // <compare>