[yul-phaser] Program: Output operator for ErrorList

- It does not seem universal enough to put it in liblangutil but in the scope of yul-phaser it's generic enough so I'm going to keep it together with Program.

tools/yulPhaser/Program.cpp

@@ -22,6 +22,7 @@
 #include <liblangutil/CharStream.h>
 #include <liblangutil/ErrorReporter.h>
 #include <liblangutil/Exceptions.h>
+#include <liblangutil/SourceReferenceFormatter.h>
 
 #include <libyul/AsmAnalysis.h>
 #include <libyul/AsmAnalysisInfo.h>
@@ -57,6 +58,16 @@ ostream& operator<<(ostream& _stream, Program const& _program);
 
 }
 
+ostream& std::operator<<(ostream& _outputStream, ErrorList const& _errors)
+{
+	SourceReferenceFormatter formatter(_outputStream);
+
+	for (auto const& error: _errors)
+		formatter.printErrorInformation(*error);
+
+	return _outputStream;
+}
+
 Program::Program(Program const& program):
 	m_ast(make_unique<Block>(get<Block>(ASTCopier{}(*program.m_ast)))),
 	m_dialect{program.m_dialect},

tools/yulPhaser/Program.h

@@ -41,6 +41,13 @@ struct Dialect;
 
 }
 
+namespace std
+{
+
+std::ostream& operator<<(std::ostream& _outputStream, solidity::langutil::ErrorList const& _errors);
+
+}
+
 namespace solidity::phaser
 {