doc: add relnote fragment on stack slot merging

Add a blurb to the toolchain section talking about stack slot merging.

Updates #62737.

Change-Id: I26193a6a381c95ff5d79ce80b77c10c7561d00cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/581439
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>

diff --git a/doc/next/5-toolchain.md b/doc/next/5-toolchain.md
index ce763f1b93827b02806f56aca501977a4c3a20fd..7f547f686b2629dad459dbb99b376d715c20fc6d 100644 (file)
--- a/doc/next/5-toolchain.md
+++ b/doc/next/5-toolchain.md
@@ -4,6 +4,11 @@ The build time overhead to building with [Profile Guided Optimization](/doc/pgo)
 Previously, large builds could see 100%+ build time increase from enabling PGO.
 In Go 1.23, overhead should be in the single digit percentages.
 
+<!-- https://go.dev/issue/62737 , https://golang.org/cl/576681,  https://golang.org/cl/577615 -->
+The compiler in Go 1.23 can now overlap the stack frame slots of local variables
+accessed in disjoint regions of a function, which reduces stack usage
+for Go applications.
+
 ## Assembler {#assembler}
 
 ## Linker {#linker}