IR: Print SSA values as %123 instead of %ssa123

This is less noisy with no loss of clarity, and follows the notation
used by both LLVM IR and NIR. (So, it should be familiar.)

Change done with:

    sed -i -e 's/%ssa/%/g' $(git grep -l '%ssa')

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>

External/FEXCore/Source/Interface/IR/IRParser.cpp

@@ -413,7 +413,7 @@ class IRParser: public FEXCore::IR::IREmitter {
       }
 
       // Check if we are pulling in some IR from the IR Printer
-      // Prints (%ssa%d) at the start of lines without a definition
+      // Prints (%%d) at the start of lines without a definition
       if (Line[0] == '(') {
         size_t DefinitionEnd = fextl::string::npos;
         if ((DefinitionEnd = Line.find_first_of(')', CurrentPos)) != fextl::string::npos) {