[chore] Ability to provide custom ld and gc flags

[Dainerx]

Description

The primary purpose of this PR is to provide greater flexibility in how OTEL binaries are built, enabling the inclusion of debugging symbols when needed, without always stripping them by default.

Currently, debugging symbols are only retained when debug_compilation=true. However, this approach also disables all compiler inlining and optimizations (gcflags=all=-N -l) to ensure an exact match between written and executed code, resulting in a significant increase in CPU consumption. There are scenarios where we want binaries with debugging symbols and DWARF information while still allowing the compiler to optimize and inline. This PR addresses that need by introducing configurable GCFlags.

ocb --ldflags="" --gcflags="" --config=builder-config.yaml

Link to tracking issue

Fixes #58

Testing

Manual

Override LDflags:

Override both

Documentation

README file updated.

--

Backward compatibility concerns:

• As of today, passing cfg.LDFlags will append to LD flags that are by default to -s -w.

Questions:

• Should we deprecate DebugCompilation property?

[codecov]

Codecov Report

Attention: Patch coverage is 48.00000% with 13 lines in your changes missing coverage. Please review.

Project coverage is 91.62%. Comparing base (ffcef93) to head (6375e02).
Report is 45 commits behind head on main.

Files with missing lines	Patch %	Lines
cmd/builder/internal/builder/main.go	42.85%	6 Missing and 2 partials ⚠️
cmd/builder/internal/command.go	54.54%	4 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##             main   #11996    +/-   ##
========================================
  Coverage   91.62%   91.62%            
========================================
  Files         447      455     +8     
  Lines       23739    24057   +318     
========================================
+ Hits        21751    22043   +292     
- Misses       1613     1639    +26     
  Partials      375      375            

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[mx-psi]

Instead of TODOs in code, please file an issue :)

Suggested change

	DebugCompilation bool `mapstructure:"debug_compilation"` // TODO depercate?
	DebugCompilation bool `mapstructure:"debug_compilation"`

[mx-psi]

Suggested change

	By default, the LDflags are set to -s -w, which strips debugging symbols to produce a smaller OpenTelemetry Collector binary. To retain debugging symbols and DWARF debugging data in the binary, override the LDflags as shown:
	By default, the LDflags are set to `-s -w`, which strips debugging symbols to produce a smaller OpenTelemetry Collector binary. To retain debugging symbols and DWARF debugging data in the binary, override the LDflags as shown: