Incomplete decompilation in golang binary

[farvend]

Version and Platform (required):

• Binary Ninja Version: 5.2.8286-dev
• Edition: Non-Commercial
• OS: Windows
• OS Version: 10
• CPU Architecture: x64

Bug Description:
BInary NInja doesn't fully decompile the main function, decompiler output ends at runtime.ncpu_3 = runtime.ncpu_3;, but there is more code. The bug happens because MLIL thinks that branch at 0x004cdc90 is always false

Steps To Reproduce:

1. Open asd.exe
2. Go to main.main function
3. Open Pseudo C and MLIL (or any other lower BNIL)
4. Go to 0x004cdbe9
5. See that in MLIL there is more code.

Expected Behavior:
Full decompilation of main function

Binary:
asd.zip

[emesare]

Related to #5840

Forwarding response from @bdash on slack:

It looks like the calling convention that is applied to os/exec.Command or os/exec.(*Cmd).Output does not reflect the registers that Go uses for return values and so rdi is assumed to be unmodified from its previous value. This means the test at 0x004cdc90 is always false and one side of the conditional branch is unreachable.