Emit a better error when running out of registers on inline asm.

The most likely case where this error happens is when the user specifies
too many register operands. Don't make it look like an internal LLVM bug
when we can see that the error is coming from an inline asm instruction.
For other instructions we keep the "ran out of registers" error.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192041 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/RegAllocBase.cpp b/lib/CodeGen/RegAllocBase.cpp
index a912414..3ee58d4 100644
--- a/lib/CodeGen/RegAllocBase.cpp
+++ b/lib/CodeGen/RegAllocBase.cpp
@@ -106,7 +106,6 @@
 
     if (AvailablePhysReg == ~0u) {
       // selectOrSplit failed to find a register!
-      const char *Msg = "ran out of registers during register allocation";
       // Probably caused by an inline asm.
       MachineInstr *MI;
       for (MachineRegisterInfo::reg_iterator I = MRI->reg_begin(VirtReg->reg);
@@ -114,9 +113,9 @@
         if (MI->isInlineAsm())
           break;
       if (MI)
-        MI->emitError(Msg);
+        MI->emitError("inline assembly requires more registers than available");
       else
-        report_fatal_error(Msg);
+        report_fatal_error("ran out of registers during register allocation");
       // Keep going after reporting the error.
       VRM->assignVirt2Phys(VirtReg->reg,
                  RegClassInfo.getOrder(MRI->getRegClass(VirtReg->reg)).front());