Update linux-x86 Go prebuilts from ab/8921581

https://ci.android.com/builds/branches/aosp-build-tools-release/grid?head=8921581&tail=8921581

Update script: toolchain/go/update-prebuilts.sh

Test: Treehugger presubmit
Change-Id: Ieac5e31af3fa5d5e6122345d7e22913f1e187662
diff --git a/src/run.rc b/src/run.rc
index a7b4801..2a0bb7f 100755
--- a/src/run.rc
+++ b/src/run.rc
@@ -10,11 +10,7 @@
 	exit wrongdir
 }
 
-eval `{../bin/go env}
+eval `{../bin/go tool dist env}
 
 GOPATH=/nonexist-gopath
-GOBIN=() # Issue 14340
-GOFLAGS=()
-GO111MODULE=()
-
 exec ../bin/go tool dist test -rebuild $*