New warnings for Win64 target

[NightStrike]

Compiling for target=x86_64-pc-mingw32 yields these warnings that
didn't appear prior to my last set of builds earlier in April (around
the 17th):

../../../gcc/libgfortran/generated/reshape_i4.c: In function 'reshape_4':
../../../gcc/libgfortran/generated/reshape_i4.c:134: warning:
statement with no effect
../../../gcc/libgfortran/generated/reshape_i8.c: In function 'reshape_8':
../../../gcc/libgfortran/generated/reshape_i8.c:134: warning:
statement with no effect
../../../gcc/libgfortran/generated/reshape_i16.c: In function 'reshape_16':
../../../gcc/libgfortran/generated/reshape_i16.c:134: warning:
statement with no effect
../../../gcc/libgfortran/generated/reshape_r4.c: In function 'reshape_r4':
../../../gcc/libgfortran/generated/reshape_r4.c:134: warning:
statement with no effect
../../../gcc/libgfortran/generated/reshape_r8.c: In function 'reshape_r8':
../../../gcc/libgfortran/generated/reshape_r8.c:134: warning:
statement with no effect
../../../gcc/libgfortran/generated/reshape_r10.c: In function 'reshape_r10':
../../../gcc/libgfortran/generated/reshape_r10.c:134: warning:
statement with no effect
../../../gcc/libgfortran/generated/reshape_c4.c: In function 'reshape_c4':
../../../gcc/libgfortran/generated/reshape_c4.c:134: warning:
statement with no effect
../../../gcc/libgfortran/generated/reshape_c8.c: In function 'reshape_c8':
../../../gcc/libgfortran/generated/reshape_c8.c:134: warning:
statement with no effect
../../../gcc/libgfortran/generated/reshape_c10.c: In function 'reshape_c10':
../../../gcc/libgfortran/generated/reshape_c10.c:134: warning:
statement with no effect