[llvm] r174054 - Add AArch64 as an experimental target.

[Anton Yartsev]

Hi Tim,

Failed to build LLVM under VS2008 since this commit.
I have so far used ugly workaround locally and forgot to report the 
problem, now when I got clean sources the problem exposed again.
Here is the log:

2>------ Build started: Project: LLVMAArch64CodeGen, Configuration: 
Debug Win32 ------
2>Compiling...
2>AArch64InstrInfo.cpp
3>------ Build started: Project: LLVMHexagonCodeGen, Configuration: 
Debug Win32 ------
3>Compiling...
3>HexagonHardwareLoops.cpp
2>..\..\..\..\lib\Target\AArch64\AArch64InstrInfo.cpp(621) : error 
C2668: 'abs' : ambiguous call to overloaded function
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(539): could be 'long double abs(long double)'
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(491): or       'float abs(float)'
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(487): or       'double abs(double)'
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(485): or       'long abs(long)'
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(103): or       'int abs(int)'
2>        while trying to match the argument list '(int64_t)'
2>..\..\..\..\lib\Target\AArch64\AArch64InstrInfo.cpp(625) : error 
C2668: 'abs' : ambiguous call to overloaded function
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(539): could be 'long double abs(long double)'
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(491): or       'float abs(float)'
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(487): or       'double abs(double)'
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(485): or       'long abs(long)'
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(103): or       'int abs(int)'
2>        while trying to match the argument list '(int64_t)'
2>..\..\..\..\lib\Target\AArch64\AArch64InstrInfo.cpp(676) : error 
C2668: 'abs' : ambiguous call to overloaded function
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(539): could be 'long double abs(long double)'
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(491): or       'float abs(float)'
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(487): or       'double abs(double)'
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(485): or       'long abs(long)'
2>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(103): or       'int abs(int)'
2>        while trying to match the argument list '(int64_t)'
2>Build log was saved at 
"file://f:\llvm_COMMON\-VS_build-\lib\Target\AArch64\LLVMAArch64CodeGen.dir\Debug\BuildLog.htm"
2>LLVMAArch64CodeGen - 3 error(s), 0 warning(s)

The similar problem with Hexagon:

3>..\..\..\..\lib\Target\Hexagon\HexagonHardwareLoops.cpp(704) : error 
C2668: 'abs' : ambiguous call to overloaded function
3>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(539): could be 'long double abs(long double)'
3>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(491): or       'float abs(float)'
3>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(487): or       'double abs(double)'
3>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(485): or       'long abs(long)'
3>        C:\Program Files\Microsoft Visual Studio 
9.0\VC\include\math.h(103): or       'int abs(int)'
3>        while trying to match the argument list '(int64_t)'
3>Build log was saved at 
"file://f:\llvm_COMMON\-VS_build-\lib\Target\Hexagon\LLVMHexagonCodeGen.dir\Debug\BuildLog.htm"
3>LLVMHexagonCodeGen - 1 error(s), 0 warning(s)