[tools/rexm] Respect RAYLIB_LIBTYPE=STATIC during desktop linking

[TheLazyIndianTechie]

Summary

Fix tools/rexm/Makefile so desktop builds actually honor RAYLIB_LIBTYPE=STATIC when selecting the raylib library to link.

Before this change, RAYLIB_LIBTYPE defaulted to STATIC but LDLIBS still used -lraylib, which can resolve to a shared library when one is present in src.

Problem Reproduction

Environment: macOS (clang), working from repository root.

1. Build raylib shared library:

   cd src
   make PLATFORM=PLATFORM_DESKTOP RAYLIB_LIBTYPE=SHARED CUSTOM_CFLAGS="-DGL_SILENCE_DEPRECATION" -B

2. Build and run rexm with defaults:

   cd ../tools/rexm
   make clean && make
   ./rexm validate ../../examples/examples.h

3. Runtime failure:

   dyld: Library not loaded: @rpath/libraylib.550.dylib
   Referenced from: .../tools/rexm/rexm
   Reason: no LC_RPATH's found
   

Root Cause

tools/rexm/Makefile sets RAYLIB_LIBTYPE ?= STATIC, but for desktop targets it still links with -lraylib, allowing the linker to pick a shared artifact when available.

Fix

• Added RAYLIB_LINK_LIB:
  • $(RAYLIB_LIB_PATH)/libraylib.a when RAYLIB_LIBTYPE=STATIC
  • -lraylib otherwise
• Replaced desktop LDLIBS raylib entry to use $(RAYLIB_LINK_LIB) on Windows/Linux/macOS/BSD.

Validation

• make clean && make in tools/rexm now links explicitly to ../../src/libraylib.a by default.
• otool -L ./rexm no longer shows a dynamic libraylib dependency in static mode.
• ./rexm --help and ./rexm validate ../../examples/examples.h run successfully in static mode, even with shared raylib artifacts present in src.

Scope

Small Makefile-only change in tools/rexm/Makefile; no behavior changes outside library selection for linking.

[raysan5]

Both lines are exactly the same, not sure how it has been tested.