Use slices of pointers in pprofile (open-telemetry#11339)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

All these slices of values have a potential to store large amounts of
data, and should therefore be slices of pointers.

<!-- Issue number if applicable -->
#### Link to tracking issue
Fixes open-telemetry#11281

cc @mx-psi @bogdandrutu

.chloggen/pprofile-slice-ptrs.yaml

@@ -0,0 +1,20 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: 'breaking'
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: pdata/pprofile
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Replace slices of values to slices of pointers for the `Mapping`, `Location`, `Line`, `Function`, `AttributeUnit`, `Link`, `Value`, `Sample` and `Labels` attributes.
+
+# One or more tracking issues or pull requests related to the change
+issues: [11339]
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [api]

pdata/internal/cmd/pdatagen/internal/pprofile_package.go

@@ -230,7 +230,7 @@ var profile = &messageValueStruct{
 	},
 }
 
-var valueTypeSlice = &sliceOfValues{
+var valueTypeSlice = &sliceOfPtrs{
 	structName: "ValueTypeSlice",
 	element:    valueType,
 }
@@ -261,7 +261,7 @@ var valueType = &messageValueStruct{
 	},
 }
 
-var sampleSlice = &sliceOfValues{
+var sampleSlice = &sliceOfPtrs{
 	structName: "SampleSlice",
 	element:    sample,
 }
@@ -318,7 +318,7 @@ var sample = &messageValueStruct{
 	},
 }
 
-var labelSlice = &sliceOfValues{
+var labelSlice = &sliceOfPtrs{
 	structName: "LabelSlice",
 	element:    label,
 }
@@ -355,7 +355,7 @@ var label = &messageValueStruct{
 	},
 }
 
-var mappingSlice = &sliceOfValues{
+var mappingSlice = &sliceOfPtrs{
 	structName: "MappingSlice",
 	element:    mapping,
 }
@@ -441,7 +441,7 @@ var mapping = &messageValueStruct{
 	},
 }
 
-var locationSlice = &sliceOfValues{
+var locationSlice = &sliceOfPtrs{
 	structName: "LocationSlice",
 	element:    location,
 }
@@ -492,7 +492,7 @@ var location = &messageValueStruct{
 	},
 }
 
-var lineSlice = &sliceOfValues{
+var lineSlice = &sliceOfPtrs{
 	structName: "LineSlice",
 	element:    line,
 }
@@ -523,7 +523,7 @@ var line = &messageValueStruct{
 	},
 }
 
-var functionSlice = &sliceOfValues{
+var functionSlice = &sliceOfPtrs{
 	structName: "FunctionSlice",
 	element:    function,
 }
@@ -567,7 +567,7 @@ var function = &messageValueStruct{
 	},
 }
 
-var attributeUnitSlice = &sliceOfValues{
+var attributeUnitSlice = &sliceOfPtrs{
 	structName: "AttributeUnitSlice",
 	element:    attributeUnit,
 }
@@ -592,7 +592,7 @@ var attributeUnit = &messageValueStruct{
 	},
 }
 
-var linkSlice = &sliceOfValues{
+var linkSlice = &sliceOfPtrs{
 	structName: "LinkSlice",
 	element:    link,
 }