runtime/pprof: allow labels on racecall in TestLabelSystemstack

Fixes #50705.

Change-Id: I85857f836cbe58447625df6cd56756d3a69880ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/379834
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

src/runtime/pprof/pprof_test.go

@@ -1462,13 +1462,13 @@ func TestLabelSystemstack(t *testing.T) {
 					// runtime.isSystemGoroutine). These
 					// should never be labeled.
 					mustNotBeLabeled = true
-				case "gogo", "gosave_systemstack_switch":
-					// These are context switch critical
-					// that we can't do a full traceback
-					// from. Typically this would be
-					// covered by the runtime check below,
-					// but these symbols don't have the
-					// package name.
+				case "gogo", "gosave_systemstack_switch", "racecall":
+					// These are context switch/race
+					// critical that we can't do a full
+					// traceback from. Typically this would
+					// be covered by the runtime check
+					// below, but these symbols don't have
+					// the package name.
 					mayBeLabeled = true
 				}