some cleanup of unused macros in test files, preparing bootstrap and single header code + scripts

scripts/singleheader.ci.ps1

@@ -0,0 +1,41 @@
+[string] $type = $null
+[string] $test = $false
+
+foreach ( $arg in $args )
+{
+	if ( $arg -eq "test" )
+	{
+		$test = $true
+	}
+	else
+	{
+		$type = $arg
+	}
+}
+
+$path_root               = git rev-parse --show-toplevel
+$path_singleheader       = Join-Path $path_root singleheader
+$path_singleheader_build = Join-Path $path_singleheader build
+
+write-host "`n`nBuilding gencpp bootstrap`n"
+
+if ( -not( Test-Path $path_singleheader_build) )
+{
+# Generate build files for meta-program
+Push-Location $path_singleheader
+	$args_meson  = @()
+	$args_meson += "setup"
+	$args_meson += $path_singleheader_build
+
+	& meson $args_meson
+Pop-Location
+}
+
+# Compile meta-program
+Push-Location $path_root
+	$args_ninja = @()
+	$args_ninja += "-C"
+	$args_ninja += $path_singleheader_build
+
+	& ninja $args_ninja
+Pop-Location