Default msvc produces slower and less optimized output than when explicitly flagging with -cc msvc

[rcsaquino]

Describe the bug

Default msvc produces slower and less optimized output than when explicitly flagging with -cc msvc.

v -prod defaults to msvc in my computer as confirmed when I use -showcc. Because of this, I would assume I don't have to explicitly call -cc msvc. However, I found out that this is false due to a possible bug. I mentioned this in another thread but was kindly asked to open another thread instead. Here, it clearly shows different -showcc outputs when comparing default msvc vs explicitly stated msvc.

Expected Behavior

If -v prod defaults to msvc, it should be as if the user types v -prod -cc msvc and thus produce similar, optimized outputs.

Current Behavior

V code compiled with v -prod defaulting to msvc is not as optimized as the one compiled with v -prod -cc msvc.

Reproduction Steps

1. On a windows 11 machine with Intel i7-10750H, only have VS build tools installed so that -v prod defaults to msvc.
2. Create a cpu intensive program and compile it with a.) v -prod, and b.) v -prod -cc msvc.
3. Time the execution of both compiled executables.
4. B will be significantly faster than A because of this bug.

Possible Solution

No response

Additional Information/Context

No response

V version

V 0.3.3 93b7cc4

Environment details (OS name and version, etc.)

V full version: V 0.3.3 aee76c5.93b7cc4
OS: windows, Microsoft Windows 11 Home Single Language v22621 64-bit
Processor: 12 cpus, 64bit, little endian,
Git version: git version 2.39.1.windows.1
Git vroot status: weekly.2023.11-46-g93b7cc48
.git/config present: true

[rcsaquino]

Bump. Same issue persists on weekly.2023.38 as tested on 2 different windows machine.