Add CREDITS.md and attribution comments in code as suggested by community

Author: JkarVN

CREDITS.md

@@ -0,0 +1,46 @@
+# Credits and Attributions
+
+This modernized fork of `pcg-cpp` by **Total-Random** integrates several critical fixes and improvements from the community. Below is a list of changes and their original sources.
+
+## Community Fixes
+
+### 1. Optimized `unxorshift`
+- **Origin:** [imneme/pcg-cpp PR #82](https://github.com/imneme/pcg-cpp/pull/82)
+- **Author:** [melak47](https://github.com/melak47)
+- **Description:** Implements a more efficient inverse xorshift operation.
+
+### 2. Empty Base Class Optimization (EBCO) for MSVC
+- **Origin:** [imneme/pcg-cpp PR #66](https://github.com/imneme/pcg-cpp/pull/66)
+- **Author:** [melak47](https://github.com/melak47)
+- **Description:** Enables `__declspec(empty_bases)` on MSVC to optimize the memory footprint of RNG objects.
+
+### 3. Public `result_type` in `seed_seq_from`
+- **Origin:** [imneme/pcg-cpp commit 1eeda5f](https://github.com/imneme/pcg-cpp/commit/1eeda5f893d9595a855cdfa5d53dbbdd08c091b7)
+- **Author:** [oneill](https://github.com/imneme) (Melissa O'Neill)
+- **Description:** Makes `result_type` public to comply with the C++ `SeedSequence` concept.
+
+### 4. GCC Warning Fixes
+- **Origin:** [SupercriticalSynthesizers/pcg-cpp PR fix-gcc-warnings](https://github.com/SupercriticalSynthesizers/pcg-cpp/tree/fix-gcc-warnings)
+- **Author:** [Timo Alho](https://github.com/tialho)
+- **Description:** Resolves various GCC warnings (clz/ctz truncation) when building with `-Wall`.
+
+## Total-Random Improvements
+
+### 5. Native Windows ARM64 Support
+- **Author:** [Total-Random](https://github.com/Total-Random)
+- **Description:** Added native support for ARM64 on MSVC using `__umulh` for efficient 128-bit multiplication.
+
+### 6. Modern CMake Build System
+- **Author:** [Total-Random](https://github.com/Total-Random)
+- **Description:** Comprehensive CMake integration with `find_package` support and automated testing via `ctest`.
+
+### 7. MSVC Compatibility Fixes
+- **Author:** [Total-Random](https://github.com/Total-Random)
+- **Description:** Resolved several MSVC-specific issues:
+  - `C2678` (ambiguous operator) in `set_stream` and `operator>>`.
+  - `C4458` (declaration of 'is_mcg' hides class member).
+  - `C1090` (PDB API call failed) during parallel builds.
+  - `C4127` (conditional expression is constant) in template code.
+
+## Special Thanks
+Special thanks to **Melissa O'Neill** for creating the original PCG library and to all the community members who have proposed fixes over the years.

README.md

@@ -19,6 +19,8 @@ The original repository by Melissa O'Neill (`imneme/pcg-cpp`) has been a corners
 - **Optimized `unxorshift`**: Implemented an optimized version of the inverse xorshift operation, improving performance for large integer types.
 - **Consistent Typing**: Unified integer type handling across different platforms to avoid compiler warnings and errors.
 
+Detailed information about integrated community fixes and contributors can be found in [CREDITS.md](CREDITS.md).
+
 ## About PCG
 
 PCG is a family of simple fast space-efficient statistically good algorithms for random number generation. Unlike many common generators, it's not just "good enough" — it passes the most stringent statistical tests while being faster and smaller than most alternatives.

include/pcg_extras.hpp

@@ -261,6 +261,8 @@ inline std::istream& operator>>(std::istream& in, uint8_t& value)
  * XorShifts are invertable, but they are someting of a pain to invert.
  * This function backs them out.  It's used by the whacky "inside out"
  * generator defined later.
+ * 
+ * This optimized implementation is from imneme/pcg-cpp PR #82.
  */
 
 template <typename itype>
@@ -577,6 +579,7 @@ class seed_seq_from {
     RngType rng_;
 
 public:
+    // This fix is from imneme/pcg-cpp commit 1eeda5f
     typedef uint_least32_t result_type;
 
     template<typename... Args>

include/pcg_random.hpp

@@ -97,6 +97,7 @@
     #define PCG_ALWAYS_INLINE __forceinline
     #if defined(_MSC_FULL_VER) && _MSC_FULL_VER >= 190024210
         // available since VS 2015 Update 2/3
+        // This fix is from imneme/pcg-cpp PR #66
         #define PCG_EBO __declspec(empty_bases)
     #else
         #define PCG_EBO

include/pcg_uint128.hpp

@@ -102,6 +102,7 @@ namespace pcg_extras {
 
 #if defined(__GNUC__)   // Any GNU-compatible compiler supporting C++11 has
                         // some useful intrinsics we can use.
+                        // These bitcount_t casts are from SupercriticalSynthesizers/pcg-cpp PR fix-gcc-warnings
 
 inline bitcount_t flog2(uint32_t v)
 {