rustc_trans: take into account primitives larger than 8 bytes.

[eddyb]

Fixes #38763 by marking all "eightbytes" covered by a primitive appropriately, not just the first.

[rust-highfive]

r? @pnkfelix

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[eddyb]

r? @nagisa

[nagisa]

@bors r+

[bors]

📌 Commit 5934174 has been approved by nagisa

[bors]

☔ The latest upstream changes (presumably #47209) made this pull request unmergeable. Please resolve the merge conflicts.

[eddyb]

@bors r=nagisa

[bors]

📌 Commit cbeebc5 has been approved by nagisa

[kennytm]

@bors r-

This PR failed in the rollup #47748 because Emscripten doesn't support i128. Please apply 68f2e1e:

From 68f2e1ebf2e0f959685fbce3f69349b3e21f34cc Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Thu, 25 Jan 2018 21:04:01 -0800
Subject: [PATCH] Ignore an i128 test on emscripten

---
 src/test/run-pass/issue-38763.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/test/run-pass/issue-38763.rs b/src/test/run-pass/issue-38763.rs
index 4bf9513d64f9..01cc8265a399 100644
--- a/src/test/run-pass/issue-38763.rs
+++ b/src/test/run-pass/issue-38763.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-emscripten
+
 #![feature(i128_type)]
 
 #[repr(C)]

[eddyb]

@bors r=nagisa

[bors]

📌 Commit 035eee8 has been approved by nagisa

[kennytm]

Already merged as part of #47748 😀