Introduce Equal comparison in pcommon types

[dmathieu]

Description

This introduces .Equal() methods to most pcommon types, so equality comparison can be performed with no allocations.

The types Equal is added to are:

• Value
• ByteSlice
• Float64Slice
• Int32Slice
• Int64Slice
• StringSlice
• Uint64Slice
• Map
• Slice

The original intent was to add it to Value. However, to be able to handle every type in there, I had to also add it to the other types, some of which are coming too because they are auto-generated.

Link to tracking issue

Fixes #12561

Testing

Here are the results from the new benchmarks.

go test -bench=. ./...
goos: darwin
goarch: arm64
pkg: go.opentelemetry.io/collector/pdata/pcommon
cpu: Apple M1 Max
BenchmarkByteSliceEqual-10              518354892                2.216 ns/op           0 B/op          0 allocs/op
BenchmarkFloat64SliceEqual-10           536303960                2.213 ns/op           0 B/op          0 allocs/op
BenchmarkInt32SliceEqual-10             544727418                2.208 ns/op           0 B/op          0 allocs/op
BenchmarkInt64SliceEqual-10             544786770                2.218 ns/op           0 B/op          0 allocs/op
BenchmarkStringSliceEqual-10            161984316                7.491 ns/op           0 B/op          0 allocs/op
BenchmarkUInt64SliceEqual-10            543405762                2.211 ns/op           0 B/op          0 allocs/op
BenchmarkMapEqual-10                    95199063                12.37 ns/op            0 B/op          0 allocs/op
BenchmarkSliceEqual-10                  180702288                6.640 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/nil-10              583397124                2.065 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/strings-10          252571316                4.735 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/booleans-10         421377843                2.865 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/ints-10             420362413                2.861 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/ints8-10            420972375                2.867 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/ints16-10           420432676                2.865 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/ints32-10           418548438                2.871 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/ints64-10           419564282                2.868 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/uints-10            420894673                2.874 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/uints8-10           419992580                2.864 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/uints16-10          419492168                2.869 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/uints32-10          418700623                2.862 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/uints64-10          419113983                2.870 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/floats32-10         419409087                2.866 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/floats64-10         418236566                2.872 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/byte_slices-10              223578720                5.368 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/slices-10                   140243206                8.587 ns/op           0 B/op          0 allocs/op
BenchmarkValueEqual/maps-10                     72963666                16.25 ns/op            0 B/op          0 allocs/op
PASS
ok      go.opentelemetry.io/collector/pdata/pcommon     40.049s

[dmathieu]

cc @jmacd, as you asked for the change in the linked issue.

[codecov]

Codecov Report

Attention: Patch coverage is 98.93617% with 1 line in your changes missing coverage. Please review.

Project coverage is 92.20%. Comparing base (72a8471) to head (dc8bc57).

Files with missing lines	Patch %	Lines
pdata/pcommon/value.go	98.36%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #12568      +/-   ##
==========================================
+ Coverage   92.18%   92.20%   +0.02%     
==========================================
  Files         469      469              
  Lines       25395    25489      +94     
==========================================
+ Hits        23410    23503      +93     
- Misses       1574     1575       +1     
  Partials      411      411              

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