Update MSVC makefile to support compiling for WinRT using one setting.

FossilOrigin-Name: c10794bfac0989c611ec3ea98d069cb9631a7b15

Makefile.msc

@@ -15,6 +15,12 @@ USE_AMALGAMATION = 1
 #
 USE_ICU = 0
 
+# Set this non-0 to compile binaries suitable for the WinRT environment.
+# This setting does not apply to any binaries that require Tcl to operate
+# properly (i.e. the text fixture, etc).
+#
+FOR_WINRT = 0
+
 # Set this to non-0 to create and use PDBs.
 #
 SYMBOLS = 1
@@ -44,11 +50,15 @@ BCC = cl.exe
 TCC = cl.exe -W3 -DSQLITE_OS_WIN=1 -I. -I$(TOP)\src -fp:precise
 
 # When compiling the library for use in the WinRT environment,
-# the following compile-time option must be used as well to
+# the following compile-time options must be used as well to
 # disable use of Win32 APIs that are not available and to enable
 # use of Win32 APIs that are specific to Windows 8 and/or WinRT.
+# Also, we need to dynamically link to the MSVC runtime when
+# compiling for WinRT.
 #
-# TCC = $(TCC) -DSQLITE_OS_WINRT=1
+!IF $(FOR_WINRT)!=0
+TCC = $(TCC) -DSQLITE_OS_WINRT=1 -MD
+!ENDIF
 
 # The mksqlite3c.tcl and mksqlite3h.tcl scripts will pull in
 # any extension header files by default.  For non-amalgamation