SPU: basic function analysis implemented

Basic stack frame layout analysis.
Function detection in Giga mode.
Basic use of new information in SPU LLVM.

This is WIP and may not work correctly.
Optimizations include but not limited to:
 * Compiling SPU functions as native functions when eligible
 * Avoiding register context write-out

rpcs3/Emu/Cell/SPUAnalyser.h

@@ -11,6 +11,7 @@ struct spu_itype
 	static constexpr struct branch_tag{} branch{}; // Branch Instructions
 	static constexpr struct floating_tag{} floating{}; // Floating-Point Instructions
 	static constexpr struct quadrop_tag{} _quadrop{}; // 4-op Instructions
+	static constexpr struct xfloat_tag{} xfloat{}; // Instructions producing xfloat values
 
 	enum type : unsigned char
 	{
@@ -146,24 +147,26 @@ struct spu_itype
 		FMS, // quadrop_tag last
 
 		FA,
-		DFA,
 		FS,
-		DFS,
 		FM,
+		FREST,
+		FRSQEST,
+		FI,
+		CSFLT,
+		CUFLT,
+		FRDS, // xfloat_tag last
+
+		DFA,
+		DFS,
 		DFM,
 		DFMA,
 		DFNMS,
 		DFMS,
 		DFNMA,
-		FREST,
-		FRSQEST,
-		FI,
-		CSFLT,
+		FESD,
+
 		CFLTS,
-		CUFLT,
 		CFLTU,
-		FRDS,
-		FESD,
 		FCEQ,
 		FCMEQ,
 		FCGT,
@@ -252,6 +255,12 @@ struct spu_itype
 	{
 		return value >= MPYA && value <= FMS;
 	}
+
+	// Test for xfloat instruction
+	friend constexpr bool operator &(type value, xfloat_tag)
+	{
+		return value >= FMA && value <= FRDS;
+	}
 };
 
 struct spu_iflag