[CodeGen] Print "%vreg0" as "%0" in both MIR and debug output

As part of the unification of the debug format and the MIR format, avoid
printing "vreg" for virtual registers (which is one of the current MIR
possibilities).

Basically:

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E "s/%vreg([0-9]+)/%\1/g"
* grep -nr '%vreg' . and fix if needed
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E "s/ vreg([0-9]+)/ %\1/g"
* grep -nr 'vreg[0-9]\+' . and fix if needed

Differential Revision: https://reviews.llvm.org/D40420

llvm-svn: 319427
diff --git a/llvm/lib/Target/AMDGPU/SIFixSGPRCopies.cpp b/llvm/lib/Target/AMDGPU/SIFixSGPRCopies.cpp
index 34b1f75..e9b381c 100644
--- a/llvm/lib/Target/AMDGPU/SIFixSGPRCopies.cpp
+++ b/llvm/lib/Target/AMDGPU/SIFixSGPRCopies.cpp
@@ -14,46 +14,46 @@
 ///  Register Class <vsrc> is the union of <vgpr> and <sgpr>
 ///
 /// BB0:
-///   %vreg0 <sgpr> = SCALAR_INST
-///   %vreg1 <vsrc> = COPY %vreg0 <sgpr>
+///   %0 <sgpr> = SCALAR_INST
+///   %1 <vsrc> = COPY %0 <sgpr>
 ///    ...
 ///    BRANCH %cond BB1, BB2
 ///  BB1:
-///    %vreg2 <vgpr> = VECTOR_INST
-///    %vreg3 <vsrc> = COPY %vreg2 <vgpr>
+///    %2 <vgpr> = VECTOR_INST
+///    %3 <vsrc> = COPY %2 <vgpr>
 ///  BB2:
-///    %vreg4 <vsrc> = PHI %vreg1 <vsrc>, <BB#0>, %vreg3 <vrsc>, <BB#1>
-///    %vreg5 <vgpr> = VECTOR_INST %vreg4 <vsrc>
+///    %4 <vsrc> = PHI %1 <vsrc>, <BB#0>, %3 <vrsc>, <BB#1>
+///    %5 <vgpr> = VECTOR_INST %4 <vsrc>
 ///
 ///
 /// The coalescer will begin at BB0 and eliminate its copy, then the resulting
 /// code will look like this:
 ///
 /// BB0:
-///   %vreg0 <sgpr> = SCALAR_INST
+///   %0 <sgpr> = SCALAR_INST
 ///    ...
 ///    BRANCH %cond BB1, BB2
 /// BB1:
-///   %vreg2 <vgpr> = VECTOR_INST
-///   %vreg3 <vsrc> = COPY %vreg2 <vgpr>
+///   %2 <vgpr> = VECTOR_INST
+///   %3 <vsrc> = COPY %2 <vgpr>
 /// BB2:
-///   %vreg4 <sgpr> = PHI %vreg0 <sgpr>, <BB#0>, %vreg3 <vsrc>, <BB#1>
-///   %vreg5 <vgpr> = VECTOR_INST %vreg4 <sgpr>
+///   %4 <sgpr> = PHI %0 <sgpr>, <BB#0>, %3 <vsrc>, <BB#1>
+///   %5 <vgpr> = VECTOR_INST %4 <sgpr>
 ///
 /// Now that the result of the PHI instruction is an SGPR, the register
-/// allocator is now forced to constrain the register class of %vreg3 to
+/// allocator is now forced to constrain the register class of %3 to
 /// <sgpr> so we end up with final code like this:
 ///
 /// BB0:
-///   %vreg0 <sgpr> = SCALAR_INST
+///   %0 <sgpr> = SCALAR_INST
 ///    ...
 ///    BRANCH %cond BB1, BB2
 /// BB1:
-///   %vreg2 <vgpr> = VECTOR_INST
-///   %vreg3 <sgpr> = COPY %vreg2 <vgpr>
+///   %2 <vgpr> = VECTOR_INST
+///   %3 <sgpr> = COPY %2 <vgpr>
 /// BB2:
-///   %vreg4 <sgpr> = PHI %vreg0 <sgpr>, <BB#0>, %vreg3 <sgpr>, <BB#1>
-///   %vreg5 <vgpr> = VECTOR_INST %vreg4 <sgpr>
+///   %4 <sgpr> = PHI %0 <sgpr>, <BB#0>, %3 <sgpr>, <BB#1>
+///   %5 <vgpr> = VECTOR_INST %4 <sgpr>
 ///
 /// Now this code contains an illegal copy from a VGPR to an SGPR.
 ///