Remove conflicting STATIC variable from build

[howardjohn]

We currently set STATIC=0 LDFLAGS='-extldflags -static -s -w' as part of the
build. This does not make much sense, since STATIC sets LDFLAGS to
empty, so we don't pass -static -s -w.

I believe we do want to pass these flags, as they were originally added
for a reason.

Binary size changes for istioctl, agent, and pilot in mb:

114 -> 81
104 -> 75
108 -> 77

Helps with #26232

[ ] Configuration Infrastructure
[ ] Docs
[ ] Installation
[ ] Networking
[ ] Performance and Scalability
[ ] Policies and Telemetry
[ ] Security
[ ] Test and Release
[ ] User Experience
[ ] Developer Infrastructure

Pull Request Attributes

Please check any characteristics that apply to this pull request.

[ ] Does not have any changes that may affect Istio users.

[howardjohn]

/retest

[ericvn]

Possibly want to cherrypick to 1.8, or is this just an early change to get more testing for 1.9?

[sdake]

@howardjohn -

-W with no flags will strip all LDFLAGS from the compiler execution. I am not sure what the outcome is of go with this flag, however, I'd be wary of not passing any modifiers.

-s strips the binaries. I am not sure we want to strip the binaries, as debuggers would not work properly. Many systems deliver symbols independently, although I would not just strip because it was there in the past.

[sdake]

note man ld is the source.

[sdake]

fwiw, this exact set of linkage comes from stack overflow. I think its the wrong choice: https://stackoverflow.com/questions/22267189/what-does-the-w-flag-mean-when-passed-in-via-the-ldflags-option-to-the-go-comman

[nrjpoddar]

@howardjohn I would recommend adding comments around why these flags are important and affects on size if we remove them. @sdake concern here is valid that many Go programs ship with debug symbols to enable analysis via gdb or delve. However, I don’t know if we really need to support that specially if the binary is distributed per-workload and can lead to increased resource consumption. Some of these options can effect usage with profiling tools so we should ensure that we don’t end up losing out a lot of functionality.

[nrjpoddar]

Additionally, I don’t think release notes none is correct here as it’s loss of debugging capabilities for end user. I’m not sure if anyone relies on it but it’s worth mentioning it if we decide strip off symbols.