Cherry-pick: Integrating Changes from PR #126277 and #127096 #136
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…port big endian (#126277) This patch makes these functions' tests work in big endian mode: - `__aeabi_idivmod`. - `__aeabi_uidivmod`. - `__aeabi_uldivmod`. The three functions return a struct containing two fields, quotient and remainder, via *value in regs* calling convention. They differ in the integer type of each field. In the tests of the first two, a 64-bit integer is used as the return type of the call. And as consequence of the ABI rules for structs (Composite Types), the quotient resides in `r0` and the remainder in `r1` regardless of endianness. So, in order to access each component from the 64-bit integer in the caller code, care must be taken to access the correct bits as they do depend on endianness in this case. In the test of the third one, the caller code has inline assembly to access the components. This assembly code assumed little endian, so it had to be made flexible for big endian as well. `_YUGA_BIG_ENDIAN` is defined in `int_endianness.h`. It's a macro internal to compiler-rt that's in theory compatible with more toolchains than gcc and clang.
In soft floating-point ABI, this function takes the double argument as a pair of registers r0 and r1. The ordering of these two registers follow the endianness rules, therefore the register on which the bit flipping must happen depends on the endianness.
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[compiler-rt] Add support for big endian for Arm's __negdf2vfp (cherry picked from llvm/llvm-project#127096)
[compiler-rt] Fix tests of _aeabi(idivmod|uidivmod|uldivmod) to support big endian (cherry picked from llvm/llvm-project#126277)