Add some porting notes for some platforms

Author: carstene1ns

3ds/README.md

@@ -10,3 +10,13 @@
 ### Local build process:
 
 - Run `0_build_everything.sh` in a terminal
+
+## Developer's notes
+
+The 3DS supports:
+- ✘ ARM NEON intrinsiscs
+- ✘ TLS (thread local storage)
+- ✔ floating point hardware (albeit slow)
+- ✔ mediocre CPU performance and memory size
+
+These often need to be patched in or out of the libraries.

switch/README.md

@@ -10,3 +10,13 @@
 ### Local build process:
 
 - Run `0_build_everything.sh` in a terminal
+
+## Developer's notes
+
+The switch supports:
+- ✔ ARM NEON intrinsiscs
+- ✔ TLS (thread local storage)
+- ✔ PIC (position independent code)
+- ✔ floating point hardware
+
+These often need to be patched in or out of the libraries.

vita/README.md

@@ -9,3 +9,12 @@ Run `0_build_everything.sh` in a terminal
 Note: Since we overwrite some libraries from vitasdk with newer versions,
 we use our own local installation. This means you need to redefine `$VITASDK`
 when targetting our builds.
+
+## Developer's notes
+
+The switch supports:
+- ✔ ARM NEON intrinsiscs
+- ✔ floating point hardware
+- ✘ problematic file access (slow, partly unsupported posix stuff)
+
+These often need to be patched in or out of the libraries.

wii/README.md

@@ -10,3 +10,13 @@
 ### Local build process:
 
 - Run `0_build_everything.sh` in a terminal
+
+## Developer's notes
+
+The Wii supports:
+- ✘ VMX intrinsics
+- ✘ TLS (thread local storage)
+- ✔ floating point hardware (albeit slow)
+- ✘ slow CPU performance and little memory size
+
+These often need to be patched in or out of the libraries.

wiiu/README.md

@@ -10,3 +10,12 @@
 ### Local build process:
 
 - Run `0_build_everything.sh` in a terminal
+
+## Developer's notes
+
+The Wii U supports:
+- ✘ VMX intrinsics
+- ✘ TLS (thread local storage)
+- ✔ floating point hardware (slow, but present)
+
+These often need to be patched in or out of the libraries.