runtime/pprof: fix TestCPUProfileWithFork on Windows/ARM

Use smaller heap on Windows/ARM, which generally does not have
page file enabled and therefore has limited virtual address space.

Updates #26148
Signed-off-by: Jordan Rhee <jordanrh@microsoft.com>

Change-Id: I4030be24a10fab7b9b659e3736b7e83f10710bfa
Reviewed-on: https://go-review.googlesource.com/c/153719
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/runtime/pprof/pprof_test.go

@@ -321,6 +321,10 @@ func TestCPUProfileWithFork(t *testing.T) {
 		// Use smaller size for Android to avoid crash.
 		heap = 100 << 20
 	}
+	if runtime.GOOS == "windows" && runtime.GOARCH == "arm" {
+		// Use smaller heap for Windows/ARM to avoid crash.
+		heap = 100 << 20
+	}
 	if testing.Short() {
 		heap = 100 << 20
 	}