[committed] Don't pass -m32 to libcc1 on arm-linux

[Yao Qi <qiyaoltc@gmail.com>]

When I run gdb.compile/ tests on arm-linux, I get the following fails,

(gdb) compile code -- ;^M
arm-none-linux-gnueabihf-gcc: error: unrecognized command line option '-m32'; did you mean '-mbe32'?^M
Compilation failed.^M
(gdb) compile code (void) param^M
arm-none-linux-gnueabihf-gcc: error: unrecognized command line option '-m32'; did you mean '-mbe32'?^M
Compilation failed.^M
(gdb) FAIL: gdb.compile/compile-ops.exp: compile code (void) param

This patch fixes it by implementing gcc_target_options gdbarch method
for arm-linux to override option "-m32".

gdb:

2018-01-19  Yao Qi  <yao.qi@linaro.org>

	* arm-linux-tdep.c (arm_linux_gcc_target_options): New function.
	(arm_linux_init_abi): Install it.
---
 gdb/ChangeLog        |  5 +++++
 gdb/arm-linux-tdep.c | 11 +++++++++++
 2 files changed, 16 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 6709f44..53fde81 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 2018-01-19  Yao Qi  <yao.qi@linaro.org>
 
+	* arm-linux-tdep.c (arm_linux_gcc_target_options): New function.
+	(arm_linux_init_abi): Install it.
+
+2018-01-19  Yao Qi  <yao.qi@linaro.org>
+
 	* osabi.c (gdb_osabi_names): Extend the regexp for
 	arm-linux-gnueabihf.
 
diff --git a/gdb/arm-linux-tdep.c b/gdb/arm-linux-tdep.c
index d1262cc..e8f8c4e 100644
--- a/gdb/arm-linux-tdep.c
+++ b/gdb/arm-linux-tdep.c
@@ -1712,6 +1712,15 @@ arm_linux_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
   return find_solib_trampoline_target (frame, pc);
 }
 
+/* Implement the gcc_target_options gdbarch method.  */
+
+static char *
+arm_linux_gcc_target_options (struct gdbarch *gdbarch)
+{
+  /* GCC doesn't know "-m32".  */
+  return NULL;
+}
+
 static void
 arm_linux_init_abi (struct gdbarch_info info,
 		    struct gdbarch *gdbarch)
@@ -1992,6 +2001,8 @@ arm_linux_init_abi (struct gdbarch_info info,
   arm_linux_record_tdep.arg5 = ARM_A1_REGNUM + 4;
   arm_linux_record_tdep.arg6 = ARM_A1_REGNUM + 5;
   arm_linux_record_tdep.arg7 = ARM_A1_REGNUM + 6;
+
+  set_gdbarch_gcc_target_options (gdbarch, arm_linux_gcc_target_options);
 }
 
 void
-- 
1.9.1