Add a Visual Studio solution.

.gitignore

@@ -2,6 +2,7 @@
 *.*~
 .DS_Store
 
+.vs/
 .vscode
 
 bin/

Wasmtime.sln

@@ -0,0 +1,31 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.29519.181
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Wasmtime", "src\Wasmtime.csproj", "{5EB63C51-5286-4DDF-BF7F-4110CC6D80B8}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Wasmtime.Tests", "tests\Wasmtime.Tests.csproj", "{8A200114-1D0B-4F90-9F82-1FFE47C207DD}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{5EB63C51-5286-4DDF-BF7F-4110CC6D80B8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5EB63C51-5286-4DDF-BF7F-4110CC6D80B8}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5EB63C51-5286-4DDF-BF7F-4110CC6D80B8}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5EB63C51-5286-4DDF-BF7F-4110CC6D80B8}.Release|Any CPU.Build.0 = Release|Any CPU
+		{8A200114-1D0B-4F90-9F82-1FFE47C207DD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{8A200114-1D0B-4F90-9F82-1FFE47C207DD}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{8A200114-1D0B-4F90-9F82-1FFE47C207DD}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{8A200114-1D0B-4F90-9F82-1FFE47C207DD}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {F5AC35E5-1373-49E6-97DC-68CB5E0369E0}
+	EndGlobalSection
+EndGlobal