[vm/ffi] Support Linux on Arm 32-bit (hardfp)

Implement the hardfp calling convention.

Tested QEMU locally as the bots are not online yet.

tools/test.py -m debug -a arm -c dartkp --use-qemu ffi_2 ; tools/test.py -m debug -a arm -c dartk --use-qemu ffi_2
Test configuration:
    custom configuration(architecture: arm, compiler: dartkp, mode: debug, runtime: dart_precompiled, system: linux, use-qemu)
Suites tested: ffi_2
[00:45 | 100% | +  189 | -    0]
Test configuration:
    custom configuration(architecture: arm, compiler: dartk, mode: debug, runtime: vm, system: linux, use-qemu)
Suites tested: ffi_2
[09:52 | 100% | +  189 | -    0]

Fixes: dart-lang#36309

Change-Id: Ic34175bdf9b9f359f1126aeb157362e76443921a
Cq-Include-Trybots: luci.dart.try:vm-ffi-android-debug-arm-try,vm-ffi-android-debug-arm64-try,app-kernel-linux-debug-x64-try,vm-kernel-linux-debug-ia32-try,vm-kernel-win-debug-x64-try,vm-kernel-win-debug-ia32-try,vm-kernel-precomp-linux-debug-x64-try,vm-dartkb-linux-release-x64-abi-try,vm-kernel-precomp-android-release-arm64-try,vm-kernel-asan-linux-release-x64-try,vm-kernel-linux-release-simarm-try,vm-kernel-linux-release-simarm64-try,vm-kernel-precomp-android-release-arm_x64-try,vm-kernel-precomp-obfuscate-linux-release-x64-try,dart-sdk-linux-try,analyzer-analysis-server-linux-try,analyzer-linux-release-try,front-end-linux-release-x64-try,vm-kernel-precomp-win-release-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/124136
Commit-Queue: Daco Harkes <[email protected]>
Reviewed-by: Martin Kustermann <[email protected]>

Author: dcharkes

assembler_arm.cc

@@ -3160,6 +3160,13 @@ void Assembler::AddImmediateSetFlags(Register rd,
   }
 }
 
+void Assembler::SubImmediate(Register rd,
+                             Register rn,
+                             int32_t value,
+                             Condition cond) {
+  AddImmediate(rd, rn, -value, cond);
+}
+
 void Assembler::SubImmediateSetFlags(Register rd,
                                      Register rn,
                                      int32_t value,

assembler_arm.h

@@ -757,6 +757,10 @@ class Assembler : public AssemblerBase {
                             Register rn,
                             int32_t value,
                             Condition cond = AL);
+  void SubImmediate(Register rd,
+                    Register rn,
+                    int32_t value,
+                    Condition cond = AL);
   void SubImmediateSetFlags(Register rd,
                             Register rn,
                             int32_t value,