FileReader: Store files loaded by the callback under their source unit name

test/cmdlineTests/combined_json_with_base_path/args

@@ -0,0 +1 @@
+--combined-json ast --base-path . --allow-paths .

test/cmdlineTests/combined_json_with_base_path/c.sol

@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+
+contract C {}

test/cmdlineTests/combined_json_with_base_path/input.sol

@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+
+import "./c.sol";

test/cmdlineTests/combined_json_with_base_path/output

@@ -0,0 +1 @@
+{"contracts":{"combined_json_with_base_path/c.sol:C":{}},"sourceList":["combined_json_with_base_path/c.sol","combined_json_with_base_path/input.sol"],"sources":{"combined_json_with_base_path/c.sol":{"AST":{"absolutePath":"combined_json_with_base_path/c.sol","exportedSymbols":{"C":[5]},"id":6,"license":"GPL-3.0","nodeType":"SourceUnit","nodes":[{"id":4,"literals":["solidity",">=","0.0"],"nodeType":"PragmaDirective","src":"36:22:0"},{"abstract":false,"baseContracts":[],"contractDependencies":[],"contractKind":"contract","fullyImplemented":true,"id":5,"linearizedBaseContracts":[5],"name":"C","nameLocation":"69:1:0","nodeType":"ContractDefinition","nodes":[],"scope":6,"src":"60:13:0"}],"src":"36:38:0"}},"combined_json_with_base_path/input.sol":{"AST":{"absolutePath":"combined_json_with_base_path/input.sol","exportedSymbols":{"C":[5]},"id":3,"license":"GPL-3.0","nodeType":"SourceUnit","nodes":[{"id":1,"literals":["solidity",">=","0.0"],"nodeType":"PragmaDirective","src":"36:22:1"},{"absolutePath":"combined_json_with_base_path/c.sol","file":"./c.sol","id":2,"nameLocation":"-1:-1:-1","nodeType":"ImportDirective","scope":3,"sourceUnit":6,"src":"60:17:1","symbolAliases":[],"unitAlias":""}],"src":"36:42:1"}}},"version": "<VERSION REMOVED>"}