Enable the workaround for the Loongson 2F bug by default.

Patch by Mark H Weaver <mhw@netris.org>.

--- binutils/gas/config/tc-mips.c.orig	2012-09-04 10:21:03.000000000 -0400
+++ binutils/gas/config/tc-mips.c	2013-10-06 02:23:21.651983768 -0400
@@ -934,10 +934,10 @@ enum fix_vr4120_class
 };
 
 /* ...likewise -mfix-loongson2f-jump.  */
-static bool mips_fix_loongson2f_jump;
+static bool mips_fix_loongson2f_jump = FALSE;
 
 /* ...likewise -mfix-loongson2f-nop.  */
-static bool mips_fix_loongson2f_nop;
+static bool mips_fix_loongson2f_nop = TRUE;
 
 /* True if -mfix-loongson2f-nop or -mfix-loongson2f-jump passed.  */
 static bool mips_fix_loongson2f;
--- binutils/gas/testsuite/gas/mips/mips.exp.orig	2012-09-04 10:17:13.000000000 -0400
+++ binutils/gas/testsuite/gas/mips/mips.exp	2013-10-06 02:23:21.663983768 -0400
@@ -110,6 +110,12 @@ proc mips_arch_init {} {
 
     # Catch because the variable won't be set the first time through.
     catch {unset mips_arches}
+
+    # Disable the loongson2f nop fix by default, because most of the
+    # existing test cases for mips will fail otherwise.
+    global ASFLAGS
+    set old_ASFLAGS "$ASFLAGS"
+    set ASFLAGS "$ASFLAGS -mno-fix-loongson2f-nop"
 }
 
 # mips_arch_create ARCH GPRSIZE EXTENDS PROPS AS_FLAGS OBJDUMP_FLAGS \
9756658e5'>tree</a><a href='/guix/commit/build-aux/test-env.in?id=c47694f116b98ce44fce37bd0f7458b9756658e5'>commit</a><a href='/guix/diff/build-aux/test-env.in?id=c47694f116b98ce44fce37bd0f7458b9756658e5'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/build-aux/test-env.in'>
<input type='hidden' name='id' value='c47694f116b98ce44fce37bd0f7458b9756658e5'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=c47694f116b98ce44fce37bd0f7458b9756658e5'>root</a>/<a href='/guix/log/build-aux?id=c47694f116b98ce44fce37bd0f7458b9756658e5'>build-aux</a>/<a href='/guix/log/build-aux/test-env.in?id=c47694f116b98ce44fce37bd0f7458b9756658e5'>test-env.in</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/build-aux/test-env.in?id=c47694f116b98ce44fce37bd0f7458b9756658e5&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-12-22 10:53:19 +0100'>2021-12-22</span></td><td><a href='/guix/commit/build-aux/test-env.in?id=9ebc9ca070a21ba0aeb3f61202a8071bb250ccc8'>tests: Move keys into ./tests/keys/ and add a third ed25519 key.</a><span class='msg-avail'>...</span></td><td>Attila Lendvai</td></tr>
<tr><td><span title='2021-04-20 12:13:16 +0200'>2021-04-20</span></td><td><a href='/guix/commit/build-aux/test-env.in?id=d95168321f4a9bf6857b598da0a183b45a868d54'>import: Remove Nix importer.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-10-16 22:53:40 +0200'>2019-10-16</span></td><td><a href='/guix/commit/build-aux/test-env.in?id=a1aaca314ca94700ebe3449d6bd73522f2d243bc'>build: Remove references to 'NIX_LOCALSTATE_DIR'.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-10-16 22:53:40 +0200'>2019-10-16</span></td><td><a href='/guix/commit/build-aux/test-env.in?id=47e99e626b46b2fc433506a822d251de68ad6241'>daemon: Remove traces of 'NIX_ROOT_FINDER'.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-02-04 00:03:30 +0100'>2019-02-04</span></td><td><a href='/guix/commit/build-aux/test-env.in?id=a87d66f371da2a84d7bba1cae58b71c9c9af73aa'>daemon: Rename 'NIX_STATE_DIR' and 'NIX_DB_DIR' environment variables.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-05-13 23:16:16 +0200'>2018-05-13</span></td><td><a href='/guix/commit/build-aux/test-env.in?id=9e7b87ddc51c640c529d445e350c3d6ef43e301d'>build: 'test-env' does not 'guix download' non-existent files.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-04-22 23:50:49 +0200'>2018-04-22</span></td><td><a href='/guix/commit/build-aux/test-env.in?id=479c0e3f60f54e3c3a02f71efeb49119e20d2a96'>build: Fix possible race condition in 'test-env'.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-08-28 23:51:16 +0200'>2017-08-28</span></td><td><a href='/guix/commit/build-aux/test-env.in?id=4f024ef3181c5235ff11789e8c8f62722f974787'>build: Remove code to download the Guile bootstrap tarball.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>