Unicode strings broken on powerpc64 big-endian NCG

Unexpected failures:
   ghc-api/apirecomp001/apirecomp001.run          apirecomp001 [bad stderr] (normal)
   codeGen/should_run/cgrun037.run                cgrun037 [bad stdout] (g1)
   codeGen/should_run/cgrun037.run                cgrun037 [bad stdout] (normal)
   libraries/base/tests/char002.run               char002 [bad stdout] (normal)
   libraries/base/tests/IO/encoding002.run        encoding002 [bad stdout] (normal)
   libraries/base/tests/IO/encoding005.run        encoding005 [bad stdout] (normal)
   libraries/base/tests/IO/encodingerror001.run   encodingerror001 [bad stdout] (normal)
   libraries/base/tests/IO/environment001.run     environment001 [bad stdout] (normal)
   programs/galois_raytrace/galois_raytrace.run   galois_raytrace [bad exit code (1)] (normal)
   libraries/hpc/tests/raytrace/hpc_raytrace.run  hpc_raytrace [bad stderr] (normal)
   libraries/base/tests/hTell002.run              hTell002 [bad exit code (1)] (normal)
   libraries/base/tests/IO/openTempFile001.run    openTempFile001 [bad exit code (1)] (normal)
   printer/PprLinearArrow.run                     PprLinearArrow [bad exit code (2)] (normal)
   printer/PprUnicodeSyntax.run                   PprUnicodeSyntax [bad exit code (2)] (normal)
   deriving/should_run/T11535.run                 T11535 [bad stdout] (normal)
   parser/should_run/T1344.run                    T1344 [bad stdout] (normal)
   hpc/T17073.run                                 T17073 [bad stdout] (hpc)
   parser/unicode/T1744.run                       T1744 [bad stdout] (normal)
   codeGen/should_run/T2080.run                   T2080 [bad stdout] (g1)
   codeGen/should_run/T2080.run                   T2080 [bad stdout] (normal)
   libraries/base/tests/IO/T3307.run              T3307 [bad exit code (2)] (normal)
   libraries/base/tests/T4006.run                 T4006 [bad stdout] (normal)
   parser/unicode/T6016.run                       T6016 [bad exit code (1)] (normal)
   libraries/base/tests/T9395.run                 T9395 [bad stderr] (normal)
   parser/unicode/utf8_024.run                    utf8_024 [bad stdout] (normal)

These tests pass on powerpc64le.

• OS: Void Linux (ELF v2 ABI)
• architecture: powerpc64 (big-endian)