[LLDB][JIT] Set processor for ARM architecture

[kpdev42]

Summary

Patch sets ARM cpu, before compiling JIT code. This enables FastISel for armv6 and higher CPUs and allows using hardware FPU

~~~

OS Laboratory. Huawei RRI. Saint-Petersburg

[DavidSpickett]

Thanks! LGTM.

You might see some test failures for TestFPEval if anyone is testing on AIX/PPC/etc. but I think it's fine to go ahead and wait for the buildbots to complain if that is the case.

lldb/source/Utility/ArchSpec.cpp

if (IsMIPS()) {
     else if (elf_abi == "o32")
       flag |= ArchSpec::eMIPSABI_O32;
   }
   SetFlags(flag);
 }
 
 std::string ArchSpec::GetClangTargetCPU() const {
   std::string cpu;
-
   if (IsMIPS()) {
     switch (m_core) {
     case ArchSpec::eCore_mips32:
     case ArchSpec::eCore_mips32el:
       cpu = "mips32";
       break;
     case ArchSpec::eCore_mips32r2:
     case ArchSpec::eCore_mips32r2el:
if (IsMIPS()) {
     case ArchSpec::eCore_mips64r6:
     case ArchSpec::eCore_mips64r6el:
       cpu = "mips64r6";
       break;
     default:
       break;
     }
   }
+
+  if (GetTriple().isARM())
+    cpu = GetTriple().getARMCPUForArch("").str();
   return cpu;
 }
 
 uint32_t ArchSpec::GetMachOCPUType() const {
   const CoreDefinition *core_def = FindCoreDefinition(m_core);
   if (core_def) {
     const ArchDefinitionEntry *arch_def =
         FindArchDefinitionEntry(&g_macho_arch_def, core_def->core);

lldb/test/API/lang/c/fpeval/TestFPEval.py

def setUp(self):
         TestBase.setUp(self)
         self.jit_opts = lldb.SBExpressionOptions()
         self.jit_opts.SetAllowJIT(True)
         self.no_jit_opts = lldb.SBExpressionOptions()
         self.no_jit_opts.SetAllowJIT(False)
         # Find the line number to break inside main().
         self.line = line_number('main.c', '// Set break point at this line.')
 
-    @skipIf(archs=no_match(['amd64', 'x86_64', 'arm64'])) # lldb jitter incorrectly evals function with FP args on 32 bit arm
     def test(self):
         """Test floating point expressions while jitter is disabled."""
         self.build()
         exe = self.getBuildArtifact("a.out")
         self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)
 
         # Break inside the main.
         lldbutil.run_break_set_by_file_and_line(