Add powerpc64 and powerpc64le support
This adds support for big endian and little endian PowerPC64.
make check runs clean apart from one big endian backtrace issue.
@@ -2044,7 +2044,7 @@ The following configurations must be defined by the implementation:
production. For example, it controls the behavior of the standard library's
`debug_assert!` macro.
* `target_arch = "..."` - Target CPU architecture, such as `"x86"`, `"x86_64"`
- `"mips"`, `"powerpc"`, `"arm"`, or `"aarch64"`.
+ `"mips"`, `"powerpc"`, `"powerpc64"`, `"powerpc64le"`, `"arm"`, or `"aarch64"`.
* `target_endian = "..."` - Endianness of the target CPU, either `"little"` or
`"big"`.
* `target_env = ".."` - An option provided by the compiler by default
