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
@@ -910,10 +910,10 @@
 };
 
 /* ...likewise -mfix-loongson2f-jump.  */
-static bfd_boolean mips_fix_loongson2f_jump;
+static bfd_boolean mips_fix_loongson2f_jump = FALSE;
 
 /* ...likewise -mfix-loongson2f-nop.  */
-static bfd_boolean mips_fix_loongson2f_nop;
+static bfd_boolean mips_fix_loongson2f_nop = TRUE;
 
 /* True if -mfix-loongson2f-nop or -mfix-loongson2f-jump passed.  */
 static bfd_boolean 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
@@ -91,6 +91,12 @@
 
     # 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 \
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<tr><td><span title='2019-05-06 23:21:33 +0200'>2019-05-06</span></td><td><a href='/guix/commit/m4?id=fea338c6ca1922097fa233be85f424c152a4f507'>Add (guix lzlib).</a><span class='msg-avail'>...</span></td><td>Pierre Neidhardt</td></tr>
<tr><td><span title='2018-11-23 15:42:00 +0100'>2018-11-23</span></td><td><a href='/guix/commit/m4?id=60e1c1099fc3d73ed7d3235e71aae5d00ab7d773'>Update Guile-SQLite3 URL everywhere.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-09-04 17:25:11 +0200'>2018-09-04</span></td><td><a href='/guix/commit/m4?id=ca719424455465fca4b872c371daf2a46de88b33'>Switch to Guile-Gcrypt.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-06-01 15:35:15 +0200'>2018-06-01</span></td><td><a href='/guix/commit/m4?id=d59e75f3b5b82692bd250a1a3a9965397bb588c5'>build: Check for Guile-SQLite3.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-02-26 18:19:34 +0100'>2018-02-26</span></td><td><a href='/guix/commit/m4?id=1d84d7bf6052c0c80bd212d4524876576e9817d4'>build: Require Guile &gt;= 2.0.13.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-01-06 14:45:01 +0100'>2018-01-06</span></td><td><a href='/guix/commit/m4?id=142182514b84ee233bc27e574df2ca2074291525'>build: Detect broken 'equal?' in Guile 2.2.1.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>