[PATCH] sim: mips/ppc/riscv: re-add AC_CANONICAL_SYSTEM [PR sim/29439]

These configure scripts check $target and change behavior.  They
shouldn't be doing that, but until we can rework the sim to change
behavior based on the input ELF, restore AC_CANONICAL_SYSTEM to
these so that $target is correctly populated.

This was lost in the d3562f83a7b8a1ae6e333cd5561419d3da18fcb4
("sim: unify toolchain probing logic") refactor as the logic was
hoisted up to the common code.  But the fact the vars weren't
passed down to the sub-configure scripts was missed.

Bug: https://sourceware.org/PR29439
---
 sim/mips/configure     | 158 +++++++++++++++++++++++++++++++++++++++++
 sim/mips/configure.ac  |   4 ++
 sim/ppc/configure      | 129 +++++++++++++++++++++++++++++++++
 sim/ppc/configure.ac   |   4 ++
 sim/riscv/configure    | 158 +++++++++++++++++++++++++++++++++++++++++
 sim/riscv/configure.ac |   4 ++
 6 files changed, 457 insertions(+)

diff --git a/sim/mips/configure.ac b/sim/mips/configure.ac
index 96806424958c..bdc675842d38 100644
--- a/sim/mips/configure.ac
+++ b/sim/mips/configure.ac
@@ -2,6 +2,10 @@ dnl Process this file with autoconf to produce a configure script.
 AC_INIT(Makefile.in)
 AC_CONFIG_MACRO_DIRS([../m4 ../.. ../../config])
 
+dnl The sim shouldn't be checking $target and changing behavior.  But it is,
+dnl and until we clean that up, we need to expand --target for use below.
+AC_CANONICAL_SYSTEM
+
 # DEPRECATED
 #
 # Instead of defining a `subtarget' macro, code should be checking
diff --git a/sim/ppc/configure.ac b/sim/ppc/configure.ac
index 75232006e94a..b5909b705719 100644
--- a/sim/ppc/configure.ac
+++ b/sim/ppc/configure.ac
@@ -5,6 +5,10 @@ AC_CONFIG_MACRO_DIRS([../.. ../../config])
 AC_PROG_INSTALL
 AC_PROG_CC
 
+dnl The sim shouldn't be checking $target and changing behavior.  But it is,
+dnl and until we clean that up, we need to expand --target for use below.
+AC_CANONICAL_SYSTEM
+
 AC_ARG_ENABLE(sim-bitsize,
 [  --enable-sim-bitsize=n		Specify target bitsize (32 or 64).],
 [case "${enableval}" in
diff --git a/sim/riscv/configure.ac b/sim/riscv/configure.ac
index 6edb28c863ed..0e74a1edda5c 100644
--- a/sim/riscv/configure.ac
+++ b/sim/riscv/configure.ac
@@ -2,6 +2,10 @@ dnl Process this file with autoconf to produce a configure script.
 AC_INIT(Makefile.in)
 AC_CONFIG_MACRO_DIRS([../m4 ../.. ../../config])
 
+dnl The sim shouldn't be checking $target and changing behavior.  But it is,
+dnl and until we clean that up, we need to expand --target for use below.
+AC_CANONICAL_SYSTEM
+
 # Select the bitsize of the target.
 riscv_addr_bitsize=
 case "${target}" in
-- 
2.37.3