On windows cargo and rustc only works when called with lowercase extensions

[EPashkin]

By process monitor process cargo.exe tried find file cargo.EXE.exe in PATH folders and failed,
and next do same with CARGO.EXE.EXE

D:\>rustup --version
rustup 1.0.0 (17b6d21 2016-12-15)

D:\>rustup.Exe --version
rustup 1.0.0 (17b6d21 2016-12-15)

D:\>cargo --version
error: command failed: 'cargo.EXE'
info: caused by: File not found. (os error 2)

D:\>cargo.EXE --version
error: command failed: 'cargo.EXE'
info: caused by: File not found. (os error 2)

D:\>cargo.EXe --version
error: command failed: 'cargo.EXe'
info: caused by: File not found. (os error 2)

D:\>cargo.exe --version
cargo 0.16.0-nightly (ddb5c32 2016-12-16)

D:\>rustc --version
error: command failed: 'rustc.EXE'
info: caused by: File not found. (os error 2)

D:\>rustc.exe --version
rustc 1.15.0-nightly (71c06a56a 2016-12-18)

D:\>set RUST_BACKTRACE=1

D:\>cargo --version
error: command failed: 'cargo.EXE'
info: caused by: File not found. (os error 2)
info: backtrace:

stack backtrace:
   0:   0x541796 - <no info>
   1:   0x437c31 - <no info>
   2:   0x43658d - <no info>
   3:   0x439afc - <no info>
   4:   0x4013de - <no info>
   5: 0x76da62c4 - BaseThreadInitThunk
   6: 0x76fe0fd9 - RtlSubscribeWnfStateChangeNotification

PS. Actual caused by was Не удается найти указанный файл in russian but I changed it to clarify
PPS. Installed nightly x86_64-pc-windows-gnu toolchain with already installed msys64

[EPashkin]

Related to #861